120
TIME STUDY Prof.Dr.Yasemin Claire ERENSAL
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TIME STUDY
ProfDrYasemin Claire ERENSAL
Time Study
Time Study is a method used to determine
the time required by a qualified person
working at a normal pace to do a specified
task
The Concept of a Labor Standard
bull An average experienced operatorbull Working with good skill and effortbull Using a predetermined and documented methodbull To complete an operationbull At an acceptable quality levelbull The standard represents the expected time for
ndash The standard does not include rework repairndash scrap repeated iteration of work or any activity not
directly related to task completion the ldquofirst time throughrdquo
Some Uses for Standards
bull Determine total labor cost of the productbull Determine the size of the work forcebull Assess quantity of production machinery andbull equipment requiredbull Determine overall ldquothroughputrdquo timebull Assist in development of production schedulesbull Set production goals and assess performancebull Determine pay policiesbull Assess improvement possibilitiesbull Check efficiency of the individualorganization
Generally before a work measurement program is developed employees must be convinced it has aneed and will produce desirable results
Work Measurement Program
Time Study
bull Definition Time study is used to determine the time required by a qualified well trained person working at a normal pace to perform a specified task Time Study results in a Time Standard
bull Standard includesndash standardized methodndash normal pacendash time standard includes considerations of
personal time rest to overcome fatigue and time for unavoidable delays
bull Labor standards are based on observing worker doing taskndash Observe only a sample of workndash Use average time amp pace amp allowances in
order to set standard
bull Disadvantagesndash Requires a trained amp experienced analystndash Standard cannot be set before task is
performed
Time Studies
Which jobs are suitable for Time Study
bull Job performed by a single worker in a fixed location
bull Job involves repetitive short cycles
bull Job expected to continue unchanged for a long period
bull Job produces large quantities of output
bull Resulting time standard must be very accurate
Is also known as Stopwatch Time Study
bull Pioneered by Fredrich W Taylor around 1880
bull Several types employedndash Snapback in one hundredths of a minutendash Continuous in one hundredths of a minutendash Three watches continuous watchesndash Digital in one thousandths of a minutendash TMU (Time-measured units) in one
hundred thousandths of an hourndash Computer in one thousandths of a minute
Equipment
bull Stopwatchndash Decimal minute watch ndash 100 divisions (01
minute)bull Provides continuous or snapback timing
ndash Electronic watch ndash accuracy of 001 second (600 times more accurate)
bull Provides both continuous and snapback timing
ndash Computer Assisted Electronic Stopwatch
Equipment (conrsquot)
bull Video cameras
bull Time study board
bull Time study forms (TP)
bull Time study Software
bull Training equipment
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Time Study
Time Study is a method used to determine
the time required by a qualified person
working at a normal pace to do a specified
task
The Concept of a Labor Standard
bull An average experienced operatorbull Working with good skill and effortbull Using a predetermined and documented methodbull To complete an operationbull At an acceptable quality levelbull The standard represents the expected time for
ndash The standard does not include rework repairndash scrap repeated iteration of work or any activity not
directly related to task completion the ldquofirst time throughrdquo
Some Uses for Standards
bull Determine total labor cost of the productbull Determine the size of the work forcebull Assess quantity of production machinery andbull equipment requiredbull Determine overall ldquothroughputrdquo timebull Assist in development of production schedulesbull Set production goals and assess performancebull Determine pay policiesbull Assess improvement possibilitiesbull Check efficiency of the individualorganization
Generally before a work measurement program is developed employees must be convinced it has aneed and will produce desirable results
Work Measurement Program
Time Study
bull Definition Time study is used to determine the time required by a qualified well trained person working at a normal pace to perform a specified task Time Study results in a Time Standard
bull Standard includesndash standardized methodndash normal pacendash time standard includes considerations of
personal time rest to overcome fatigue and time for unavoidable delays
bull Labor standards are based on observing worker doing taskndash Observe only a sample of workndash Use average time amp pace amp allowances in
order to set standard
bull Disadvantagesndash Requires a trained amp experienced analystndash Standard cannot be set before task is
performed
Time Studies
Which jobs are suitable for Time Study
bull Job performed by a single worker in a fixed location
bull Job involves repetitive short cycles
bull Job expected to continue unchanged for a long period
bull Job produces large quantities of output
bull Resulting time standard must be very accurate
Is also known as Stopwatch Time Study
bull Pioneered by Fredrich W Taylor around 1880
bull Several types employedndash Snapback in one hundredths of a minutendash Continuous in one hundredths of a minutendash Three watches continuous watchesndash Digital in one thousandths of a minutendash TMU (Time-measured units) in one
hundred thousandths of an hourndash Computer in one thousandths of a minute
Equipment
bull Stopwatchndash Decimal minute watch ndash 100 divisions (01
minute)bull Provides continuous or snapback timing
ndash Electronic watch ndash accuracy of 001 second (600 times more accurate)
bull Provides both continuous and snapback timing
ndash Computer Assisted Electronic Stopwatch
Equipment (conrsquot)
bull Video cameras
bull Time study board
bull Time study forms (TP)
bull Time study Software
bull Training equipment
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
The Concept of a Labor Standard
bull An average experienced operatorbull Working with good skill and effortbull Using a predetermined and documented methodbull To complete an operationbull At an acceptable quality levelbull The standard represents the expected time for
ndash The standard does not include rework repairndash scrap repeated iteration of work or any activity not
directly related to task completion the ldquofirst time throughrdquo
Some Uses for Standards
bull Determine total labor cost of the productbull Determine the size of the work forcebull Assess quantity of production machinery andbull equipment requiredbull Determine overall ldquothroughputrdquo timebull Assist in development of production schedulesbull Set production goals and assess performancebull Determine pay policiesbull Assess improvement possibilitiesbull Check efficiency of the individualorganization
Generally before a work measurement program is developed employees must be convinced it has aneed and will produce desirable results
Work Measurement Program
Time Study
bull Definition Time study is used to determine the time required by a qualified well trained person working at a normal pace to perform a specified task Time Study results in a Time Standard
bull Standard includesndash standardized methodndash normal pacendash time standard includes considerations of
personal time rest to overcome fatigue and time for unavoidable delays
bull Labor standards are based on observing worker doing taskndash Observe only a sample of workndash Use average time amp pace amp allowances in
order to set standard
bull Disadvantagesndash Requires a trained amp experienced analystndash Standard cannot be set before task is
performed
Time Studies
Which jobs are suitable for Time Study
bull Job performed by a single worker in a fixed location
bull Job involves repetitive short cycles
bull Job expected to continue unchanged for a long period
bull Job produces large quantities of output
bull Resulting time standard must be very accurate
Is also known as Stopwatch Time Study
bull Pioneered by Fredrich W Taylor around 1880
bull Several types employedndash Snapback in one hundredths of a minutendash Continuous in one hundredths of a minutendash Three watches continuous watchesndash Digital in one thousandths of a minutendash TMU (Time-measured units) in one
hundred thousandths of an hourndash Computer in one thousandths of a minute
Equipment
bull Stopwatchndash Decimal minute watch ndash 100 divisions (01
minute)bull Provides continuous or snapback timing
ndash Electronic watch ndash accuracy of 001 second (600 times more accurate)
bull Provides both continuous and snapback timing
ndash Computer Assisted Electronic Stopwatch
Equipment (conrsquot)
bull Video cameras
bull Time study board
bull Time study forms (TP)
bull Time study Software
bull Training equipment
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Some Uses for Standards
bull Determine total labor cost of the productbull Determine the size of the work forcebull Assess quantity of production machinery andbull equipment requiredbull Determine overall ldquothroughputrdquo timebull Assist in development of production schedulesbull Set production goals and assess performancebull Determine pay policiesbull Assess improvement possibilitiesbull Check efficiency of the individualorganization
Generally before a work measurement program is developed employees must be convinced it has aneed and will produce desirable results
Work Measurement Program
Time Study
bull Definition Time study is used to determine the time required by a qualified well trained person working at a normal pace to perform a specified task Time Study results in a Time Standard
bull Standard includesndash standardized methodndash normal pacendash time standard includes considerations of
personal time rest to overcome fatigue and time for unavoidable delays
bull Labor standards are based on observing worker doing taskndash Observe only a sample of workndash Use average time amp pace amp allowances in
order to set standard
bull Disadvantagesndash Requires a trained amp experienced analystndash Standard cannot be set before task is
performed
Time Studies
Which jobs are suitable for Time Study
bull Job performed by a single worker in a fixed location
bull Job involves repetitive short cycles
bull Job expected to continue unchanged for a long period
bull Job produces large quantities of output
bull Resulting time standard must be very accurate
Is also known as Stopwatch Time Study
bull Pioneered by Fredrich W Taylor around 1880
bull Several types employedndash Snapback in one hundredths of a minutendash Continuous in one hundredths of a minutendash Three watches continuous watchesndash Digital in one thousandths of a minutendash TMU (Time-measured units) in one
hundred thousandths of an hourndash Computer in one thousandths of a minute
Equipment
bull Stopwatchndash Decimal minute watch ndash 100 divisions (01
minute)bull Provides continuous or snapback timing
ndash Electronic watch ndash accuracy of 001 second (600 times more accurate)
bull Provides both continuous and snapback timing
ndash Computer Assisted Electronic Stopwatch
Equipment (conrsquot)
bull Video cameras
bull Time study board
bull Time study forms (TP)
bull Time study Software
bull Training equipment
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Generally before a work measurement program is developed employees must be convinced it has aneed and will produce desirable results
Work Measurement Program
Time Study
bull Definition Time study is used to determine the time required by a qualified well trained person working at a normal pace to perform a specified task Time Study results in a Time Standard
bull Standard includesndash standardized methodndash normal pacendash time standard includes considerations of
personal time rest to overcome fatigue and time for unavoidable delays
bull Labor standards are based on observing worker doing taskndash Observe only a sample of workndash Use average time amp pace amp allowances in
order to set standard
bull Disadvantagesndash Requires a trained amp experienced analystndash Standard cannot be set before task is
performed
Time Studies
Which jobs are suitable for Time Study
bull Job performed by a single worker in a fixed location
bull Job involves repetitive short cycles
bull Job expected to continue unchanged for a long period
bull Job produces large quantities of output
bull Resulting time standard must be very accurate
Is also known as Stopwatch Time Study
bull Pioneered by Fredrich W Taylor around 1880
bull Several types employedndash Snapback in one hundredths of a minutendash Continuous in one hundredths of a minutendash Three watches continuous watchesndash Digital in one thousandths of a minutendash TMU (Time-measured units) in one
hundred thousandths of an hourndash Computer in one thousandths of a minute
Equipment
bull Stopwatchndash Decimal minute watch ndash 100 divisions (01
minute)bull Provides continuous or snapback timing
ndash Electronic watch ndash accuracy of 001 second (600 times more accurate)
bull Provides both continuous and snapback timing
ndash Computer Assisted Electronic Stopwatch
Equipment (conrsquot)
bull Video cameras
bull Time study board
bull Time study forms (TP)
bull Time study Software
bull Training equipment
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Time Study
bull Definition Time study is used to determine the time required by a qualified well trained person working at a normal pace to perform a specified task Time Study results in a Time Standard
bull Standard includesndash standardized methodndash normal pacendash time standard includes considerations of
personal time rest to overcome fatigue and time for unavoidable delays
bull Labor standards are based on observing worker doing taskndash Observe only a sample of workndash Use average time amp pace amp allowances in
order to set standard
bull Disadvantagesndash Requires a trained amp experienced analystndash Standard cannot be set before task is
performed
Time Studies
Which jobs are suitable for Time Study
bull Job performed by a single worker in a fixed location
bull Job involves repetitive short cycles
bull Job expected to continue unchanged for a long period
bull Job produces large quantities of output
bull Resulting time standard must be very accurate
Is also known as Stopwatch Time Study
bull Pioneered by Fredrich W Taylor around 1880
bull Several types employedndash Snapback in one hundredths of a minutendash Continuous in one hundredths of a minutendash Three watches continuous watchesndash Digital in one thousandths of a minutendash TMU (Time-measured units) in one
hundred thousandths of an hourndash Computer in one thousandths of a minute
Equipment
bull Stopwatchndash Decimal minute watch ndash 100 divisions (01
minute)bull Provides continuous or snapback timing
ndash Electronic watch ndash accuracy of 001 second (600 times more accurate)
bull Provides both continuous and snapback timing
ndash Computer Assisted Electronic Stopwatch
Equipment (conrsquot)
bull Video cameras
bull Time study board
bull Time study forms (TP)
bull Time study Software
bull Training equipment
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
bull Labor standards are based on observing worker doing taskndash Observe only a sample of workndash Use average time amp pace amp allowances in
order to set standard
bull Disadvantagesndash Requires a trained amp experienced analystndash Standard cannot be set before task is
performed
Time Studies
Which jobs are suitable for Time Study
bull Job performed by a single worker in a fixed location
bull Job involves repetitive short cycles
bull Job expected to continue unchanged for a long period
bull Job produces large quantities of output
bull Resulting time standard must be very accurate
Is also known as Stopwatch Time Study
bull Pioneered by Fredrich W Taylor around 1880
bull Several types employedndash Snapback in one hundredths of a minutendash Continuous in one hundredths of a minutendash Three watches continuous watchesndash Digital in one thousandths of a minutendash TMU (Time-measured units) in one
hundred thousandths of an hourndash Computer in one thousandths of a minute
Equipment
bull Stopwatchndash Decimal minute watch ndash 100 divisions (01
minute)bull Provides continuous or snapback timing
ndash Electronic watch ndash accuracy of 001 second (600 times more accurate)
bull Provides both continuous and snapback timing
ndash Computer Assisted Electronic Stopwatch
Equipment (conrsquot)
bull Video cameras
bull Time study board
bull Time study forms (TP)
bull Time study Software
bull Training equipment
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Which jobs are suitable for Time Study
bull Job performed by a single worker in a fixed location
bull Job involves repetitive short cycles
bull Job expected to continue unchanged for a long period
bull Job produces large quantities of output
bull Resulting time standard must be very accurate
Is also known as Stopwatch Time Study
bull Pioneered by Fredrich W Taylor around 1880
bull Several types employedndash Snapback in one hundredths of a minutendash Continuous in one hundredths of a minutendash Three watches continuous watchesndash Digital in one thousandths of a minutendash TMU (Time-measured units) in one
hundred thousandths of an hourndash Computer in one thousandths of a minute
Equipment
bull Stopwatchndash Decimal minute watch ndash 100 divisions (01
minute)bull Provides continuous or snapback timing
ndash Electronic watch ndash accuracy of 001 second (600 times more accurate)
bull Provides both continuous and snapback timing
ndash Computer Assisted Electronic Stopwatch
Equipment (conrsquot)
bull Video cameras
bull Time study board
bull Time study forms (TP)
bull Time study Software
bull Training equipment
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Is also known as Stopwatch Time Study
bull Pioneered by Fredrich W Taylor around 1880
bull Several types employedndash Snapback in one hundredths of a minutendash Continuous in one hundredths of a minutendash Three watches continuous watchesndash Digital in one thousandths of a minutendash TMU (Time-measured units) in one
hundred thousandths of an hourndash Computer in one thousandths of a minute
Equipment
bull Stopwatchndash Decimal minute watch ndash 100 divisions (01
minute)bull Provides continuous or snapback timing
ndash Electronic watch ndash accuracy of 001 second (600 times more accurate)
bull Provides both continuous and snapback timing
ndash Computer Assisted Electronic Stopwatch
Equipment (conrsquot)
bull Video cameras
bull Time study board
bull Time study forms (TP)
bull Time study Software
bull Training equipment
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Equipment
bull Stopwatchndash Decimal minute watch ndash 100 divisions (01
minute)bull Provides continuous or snapback timing
ndash Electronic watch ndash accuracy of 001 second (600 times more accurate)
bull Provides both continuous and snapback timing
ndash Computer Assisted Electronic Stopwatch
Equipment (conrsquot)
bull Video cameras
bull Time study board
bull Time study forms (TP)
bull Time study Software
bull Training equipment
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Equipment (conrsquot)
bull Video cameras
bull Time study board
bull Time study forms (TP)
bull Time study Software
bull Training equipment
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Daywork
Work in which pay is based on time rather than performance
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
ldquoFair Daysrsquo Workrdquo Concept
The amount of work which is expected dailyfrom an employee May be establishedsolely by management or through mutualagreement with employees or a bargainingentity It is the expected attainmentbull In some companies a Fair Dayrsquos Work isthe performance of an operator whoeffectively follows the specified method
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Basic Equipment1) Stop watch - electronic note decimal minute as opposed to seconds two modes snap (fly) back - resets to zero oneach press continuous - the time still increments (analogmore costly breakdown less accurate - time lost onmechanical snap back)2) Time study board - holding watch and necessary timestudy forms L and R-handed boards3) Time study forms ndasha)special form for recording times in a certain wayb) also a form to analyze and summarize times back in the Office
R = ratingW = watch timeOT = observed timeNT = normal time
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
May use various stopwatches ndash read in decimal minutes (except TMU)bullContinuous time study ndash short-duration jobsbullLong-cycle time study ndash long jobs (31 minutes or more) 8 hour studies (determine poor performance) or when work elements out-of-sequence
Time Study types
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Components of a Labor Standard
1048698 Observed ldquoWatchrdquo Time
1048698 Normal Time
1048698 Allowances
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Observed Time (ldquoWatch Timerdquo)
The observed and recorded time as
noted from a timing device for a worker to
perform a defined single element of an
operation
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Normal Time
Observed time (ldquoWatch Timerdquo) adjusted by
a performance rating to obtain the time
required by an average qualified worker to
perform a single element of an operation
while working at a normal pace
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Normal Time =Average Observed Time x Rating Factor
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Allowance
A percentage by which Normal Time is increased in calculation of the labor standard It usually includes minor unavoidable delays and required personal activities It may also include some provision for fatigue
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Standard Time
Normal Time adjusted by an allowance factor to
obtain the time required by an average qualified
worker to perform a single element of an
operation while working at a normal pace and
considering all normal job delays and personal
needs
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Standard Time = Normal Time (OT=ti) x Allowance
Factor (R=L)
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Typical Allowance - ldquoPF amp Drdquo
1048698 Personal
1048698 Fatigue
1048698 Delay
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Personal Allowance
An allowance in the labor standard to
provide time for the personal needs of
a worker during the workday
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Fatigue Allowance
Time included in the labor standard
calculation to allow for the effect of personal
bodily fatigue in the performance of work
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Delay Allowance
A time allowance in the labor standard
which allows for contingencies and minor
delays beyond the control of the operator
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Unavoidable Delay
A time delay which is outside the control or
responsibility of the worker
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Avoidable Delay
A time delay not allowed in the labor standard because it is not necessary to completion of the job and caused by factors under worker control
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study1 Request for time study 2 Ensure that the job is ready for time study3 Secure and record information about the operation and operator
being studied4 Divide the operation into elements and record a complete description
of the method5 Observe and record the time taken by the operator6 Determine the number of cycles to be timed7 Rate the operatorrsquos performance8 Check to make certain that a sufficient number of cycles have been
timed9 Determine the allowances10 Determine the standard time for the operation
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step1amp2
bull 1 Select job to be studied new one method changes complaints bottleneck operation incentive scheme excessive costs want to compare jobs 2 Select operator to be studied qualified (has the necessary physical attributes intelligence education skills and knowledge to carry out job in satisfactory manner without undue fatigue) vs representative (average) worker slow workers = loose times uneconomical for company fast workers = tight times unfair to workers above ground no sneaking around talk to supervisor stand businesslike attitude no opinions
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 3
3) record details about the job sketch layout info on operator working conditions
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Timing an entire operation as one single element is seldom satisfactory and an overall study is no substitute for a time study Breaking the operation down into short elements and timing each of them separately are essential parts of time study for the following reasons1 Breaking job down into short meaningful elements with clearly defined beginnings and endings makes job easier to describe2 Standard times can be determined for each element Total standard time is sum of element standard times3 Allows analyst to focus on parts of job where too much and too little time are being spent4 Operator may not work at the same tempo throughout the cycle Each element can be performance rated
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Three rules for dividing operation into elements
ndash The elements should be as short in duration as can be accurately timed
ndash Handling time should be separated from machine time
ndash Constant elements should be separated from variable elements (the term constant refers to those elements that are independent of the size weight length and shape of the workpiece)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
bull Break down into elements (for convenience of analyst better ratings) using breakpoints sight and sound relatively fine but not too small (gt04 min) types (separate within each group) a1) repetitive element occurs every cycle (sequence of activities for one unit of production) a2) occasional element not every cycle at irregular intervals a3) foreign element not necessary part of job b1) machine element performed by machine time so determined b2) manual element performed by worker c) constant vs variable depends on process leads to standard data
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Breakpoint A point in a work cycle readily distinguished
by sight or sound which is selected as the boundary between two elements in time study
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Frequency The recurrence of a work element If the element
occurs once per cycle the frequency is 11 As an example if an element is done once every six pieces then the frequency is 16 and the observed time must be divided by six when the study is summarized
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular (ldquoForeignrdquo) Elements
An element with a random usually unpredictable frequency of occurrence not part of a normal method
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements (Method Deviations) bull FumblesPart requires more work than usualbull Sticks in diebull Has to be tapped into fixturebull Excessive burrsbull Difficulty in fittingPart requires less work than usualbull No burrsbull Unusually good fit
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Irregular Elements(Interruptions Stoppages)Operator responsiblebull Blows nosebull Wipes perspirationbull Talks to othersOperator not responsiblebull Interference by othersbull Tool breakagebull Power failurebull Parts shortage
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Dividing the Operation into Elements and Recording a Description of the Method (Step 4)
Handling Irregular Elements bull Discard observations with avoidable or unalloweddelaysbull Include observation times with allowable delays inelement averagesbull Subtract the element average time from the observedtime containing the delay and prorate the delay timeover an estimated quantity (frequency of occurrence)
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Recording the Data (Timing) Step 5
Information is generally gathered by observing an operator directly or on video tape using a stopwatch
bull Continuous Timing starts the watch at the beginning of the first element and permits it to run continuously during the period of the study Observer reading of the watch at the end of element Timing is later determined by subtraction
bull Repetitive (Snap-back) Timing With repetitive or snap-back timing hands of watch are snapped back to zero at the end of each element Provides direct time for each element
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Continuous Study
A stopwatch technique in which the watch
runs continuously throughout the study
and readings are made accumulatively at
the end of each element
Making The Time Study- Recording the Data (Timing) Step 5
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
continuous timingstopwatch runs continuously read incrementedtime at each stop watch is never reset individualelement times are obtained by successivesubtraction after study is completed
Note 1) dont record decimal point2) record only two digits105=05 except if long element coveringseveral minutes
Making The Time Study- Recording the Data (Timing) Step 5
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Figure 9-7 Continuous Study
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5 O510 O5
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Recording the Data (Timing) Step 5
Continuous Study-Advantages
bull Presents a complete record for the entire observation period
bull All delays and foreign elements are recorded
bull Better adapted to record short element times
bull Clerical work required
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study
A stopwatch technique where a time value is
read and recorded at each breakpoint and
the watch is instantaneously reset to zero to
time the next element
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Recording the Data (Timing) Step 5
snap-back timingthe watch is read at the breakpoint as it is reset
next element increments from zero thus the exact elemental time is always read directly from the watch
Note 1) record only OT
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
R W OT NT
RatingWatch Time
Observed Time
Normal Time
O5O5
Making The Time Study- Recording the Data
(Timing) Step 5 Snap-back Timing
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Recording the Data (Timing) Step 5
Snapback Study Advantagesbull No clerical time needed to subtract from
the previous observations as in continuous (TP)
bull Read and record Observed Time (OT) directly
bull Short element times are difficult to timebull Possible cycle time lost during the
snapback (NA to electronic watch)
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Snapback Method
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Comparison of Time Study Modes
Mode Advantage DisadvantageSnapback 1 Direct readings
2 Easier to handle elementsout of order
1 Lose time with mechanicalwatches
2 Less accurate for shortelements
3 Temptation to adjust ratingsContinuous 1 Easier for beginners
2 Missed elements areincluded
3 Prefered by labor
1 Chance for clerical error2 More difficult to handle
elements that are out ofsequences
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Missed Breakpoints
bull Immediately mark an ldquoMrdquo in the W column
bull If operator omits an element draw a dash (-) through the applicable space in the W column
Making The Time Study- Recording the Data (Timing) Step 5
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Foreign Elementsbull Things that are external to the process that
delay the work moving forwardbull Include Supervisor interruptions power losses
defective parts leaving workstation tool breakage etchellip
bull Occurring during an element write A B C etchellipIn the NT block (TP)
Making The Time Study- Recording the Data (Timing) Step 5
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Considerations in Determining Sample Size
1 How accurate do you want to be
2 What level of confidence do you want your measurements to have
3 How much variation exists within the job elements
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
bull Any study is only a very small time
ldquosnapshotrdquo of a much longer activity
bull The less time variability between cycles the more statistically valid the study will be
bull The more the method is controlled the less time will vary between cycles
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
xhzs
n size Sample
h = accuracy level desired as percent of job element expressed as a decimal (5 = 005)
z = number of standard deviations required for the desired level of confidence
s = standard deviation of the initial sample
x = =mean of the initial sample
1
2
n
xixs Note
it
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
nzseT
2 2
196 0 030 05 0 361
10 61 11( )( )
( )( )
bull Average cycle time =0361bull Computed standard deviation = 003bull Company wants to be 95 confident that
computed time is within 5 of true average time
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
2
221
])(40
[
x
xxnn
where n is the required number of readings to predict the true time within 5 precision for 95 confidence level and n1 is the number of readings in the preliminary studyand x is the value of each readingFor 10 the value of 40 is replaced by 20 ie the sample size would reduce by a factor 4
Making The Time Study- Step 6 Sample Size - Number of Cycles Needed for Study
Special case for 5 the value of z=196 will give the constant of 40
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Common z values
Desired ConfidenceLevel ()
Z Value
9011 165
9500 196
9545 200
9911 258
9973 300990
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Often a worker speeds up (or sometimes slows down) when they know theyrsquore being observed
bull Evaluate speed or tempo of the workbull Analyst must compare the speed of the process
during the time study and analystrsquos concept of normal performance
bull Matter of judgementbull Performance rating factors are used to
subjectively assess the workerrsquos performance ndash 100 = an average work pace
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
bull Performance rating is usually based on the relative speed of the subject in performing work tasks This is called ldquoSpeed Ratingrdquo
bull The time study observer must be practiced in making judgements of operator speed Proficiency normally comes with experience and training
bull Most time study observers use videotape or film exercises to practice their performance rating skills
bull When doing a study the observer should record a performance rating for each element of work before leaving the area
bull Rating factors are normally applied in 5 incrementsbull The observer should avoid study of subjects where
performance is outside the range of 70 to 125
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
Some Benchmarks ofNormal Performance (Speed)
Walking 3 mph (264 feet in one minute)
Dealing four hands of cards in 05 minutes
Assembling 30 pegs to a pegboard in 041
minutes using two hands
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull While the analyst is collecting the time data heshe is also evaluating the ldquoqualityrdquo of the operators performance relative to that jobs ldquonormalrdquo time
bull This performance rating is somewhat subjective and is based on the complexity and difficulty of the task and the operatorrsquos skill dexterity and speed
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Rating defined Rating is an evaluation of the operatorrsquos performance in comparison to observerrsquos own concept of normal performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Standard (normal) performance - rate of output achieved by a qualified worker without overexertion adhering to the correct method over an entire day = a standard rating of 100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull However recognize that this is an average performance Have variations over time due to 1) variations in quality of material 2) changes in efficiency of tools (wear) 3) minor changes in methods (with fatigue) 4) changes in climate or working conditions
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Skill and Effort rating Introduced by Charles Bedaux based on award
of points He used 60 points to represent standard performance and effort above standard was awarded more points incentive pace was 70-85 points
bull Westinghouse rating Used a four factor system for rating the performance of the operator The operatorrsquos rating was 100 plus the sum of the positive and negative contributions in each factor area (skill effort conditions consistency)
bull Synthetic rating This is a method of evaluating operators speed from predetermined values R = Predetermined Actual
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Objective rating Observer rates speed of movement or rate of activity paying no attention to job difficulty Later adjustments are added to rating to compensate for job difficulty After judgment of pace secondary factor assigned to job indicates its relative difficulty
bull Amount of the body usedbull Foot pedalsbull Bimanual nessbull Eye-hand coordinationbull Handling or sensory requirementsbull Weight handled or resistance encounteredbull T = (P)(S)(O)
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Physiological Evaluation of Performance This approach to rating monitors heart rate and oxygen consumption in calories per minute to measure work Appropriate for medium and heavy physical tasks
bull Performance rating This is the most widely used system of rating The system is based on evaluating one single factor -- operator speed pace or tempo
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull Normalize the readings to the ldquoaverage operatorrdquo
bull Can be for the entire element or individual cycles
bull NT=OT x R100
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance
bull - For long elements- Adjust observed Time (OT) by rating (as compared to standard rating) to yield normal time (NT) (the time it takes the operator to perform the element working at standard performance)
bull OT R100 = NT 2 100100 = 2 16 125100 = 2 25 80100 = 2
bull For short elementsstudy - rate overall study
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 7 Rate the operatorrsquos performance Sources
of Error 1) Subjective rating - limited by human ability of absolute
judgement2) Standard ratings because of cultural norms - UK = 4 mph 3) Training is crucial - the more practice the better one gets a) tight rater- rates below actual difficult for workers to achieve b) loose rater - rates above actual times are easy to achieve c) conservative rater - tends to rate close to the mean loose below 100 and tight above 100 typical of beginners afraid to deviate from standard performance
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 8 Application of Allowances
bull Normal time is standard time after allowancesbull Standard time calculations can be performed in two separate ways
1 Allowances expressed as a percentage of normal time
Standard time = normal time + normal time allowances in percent
2 Allowances expressed as a percentage of total work time
Standard time = normal time 100 [100 - total allowance in of workday]
Note The second approach is the more preferred approach and many would argue the correct approach to determining allowances
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 8
Determine the allowancesbull Personal needs - personal necessities leave workplace to go to rest room get drink etc = 5
bull Basic fatigue - to account for energy expended during seated light work under good conditions = 4
bull Variable fatigue - are added to account for working conditions deviating from normal (in addition to the constant 9) based on physiological human fatigue data
bull Unavoidable allowances - to meet delays due to machine interference material irregularities etc
bull Avoidable allowances - due to socializing idleness etc
bull Extra allowances - to meet expected delays in work which because of their irregularity are uneconomical to measure (usually use work sampling here) workstation cleaning machine oiling etc
bull Policy allowance - additional allowance decided by management (not IE) to even earnings level between different levels of performance exceptional conditions due to union negotiations handicapped etc
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Personal Needsbull Those interruptions necessary to the
general well-being of the employee
bull Trips to water fountain restroom etchellip
bull Can be a function of the working environment
bull Typically 5
Making The Time Study- Step 8 Determine the allowances
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Basic Fatiguebull Accounts for the energy expenditure to
perform the given work
bull Typically 4 under Normal Conditions
Making The Time Study- Step 8 Determine the allowances
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Variable Fatiguebull Lessening of the will to workbull Can be mental or physical or a combined effectbull Factors include Noise heat humidity posture
muscular exertion tediousness general health of the worker
bull Can be directly measured by declining output production over the course of the day
Making The Time Study- Step 8 Determine the allowances
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Variable FatiguePrimary Considerationsbull Abnormal posture sitting Vsstanding Vs
bending Vsbull Muscular force time Vs exertion level recoverybull Atmospheric conditionsbull Noise and Illumination levelsbull Visual amp mental strainbull Monotony and Tediousness
Making The Time Study- Step 8 Determine the allowances
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Unavoidable Delaysbull Interruptions from supervisor dispatcher
time study technician material faults interference from servicing multiple machines
Making The Time Study- Step 8 Determine the allowances
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Avoidable Delaysbull Social visits
bull Day-dreaming
bull Idleness
bull Unnecessary work interruptions
Making The Time Study- Step 8 Determine the allowances
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Policy Allowancesbull Different performance under exceptional
circumstances
bull ADA new-employees light duty elderly etchellip
Making The Time Study- Step 8 Determine the allowances
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 8 Methods for Determining Allowances
bull Must be both accurate and correct
bull Can be calculated by Production Study or Work Sampling
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 8 Methods for Determining Allowances
Production Study bull Requires complete observation over a long
period of timebull Record specific instances of Non-Value
Added Activitybull Data must be adjusted to the normal
performance levelbull Long tedious (technician amp operator)
results may be biased
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 8 Methods for Determining Allowances
Work Samplingbull Requires a large of random observations bull Frees the technician to perform other dutiesbull No use of a stopwatch is necessarybull Technician simply records what each operator is
doingbull Yields an approximation
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 8 Methods for Determining Allowances
Work Sampling Shortfallsbull Analyst should not anticipate observations bull Confine observations to predetermined
subjectsbull Study accuracy depends on both the
number of observations and the sample scheduling
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Making The Time Study- Step 9 Determine the standard time for the operation
ObservedObservedTimeTime
ObservedObservedTimeTime
NormalNormalTimeTime
NormalNormalTimeTime
StandardStandardTimeTime
StandardStandardTimeTime
PerformancePerformanceRatingRating
PerformancePerformanceRatingRating
AllowanceAllowanceFractionFraction
AllowanceAllowanceFractionFraction
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Example 1What is the standard time for this process (4 work elements) if the allowance is 25
1 2 3 4 5 6 7 OT NT = OTPRElementEmployeePerformanceRating
090 18 17 166 191 185 177 16 1755714 =09 1756 = 158
100 69 73 68 71 153 7 64 6916667 6916667115 3 9 95 38 29 31 32 32 368090 101 111 123 99 12 119 12 1132857 1019571
NT = 2237
gard -- employee stopped to smoke cigarette ST = NT(1+AL)= 2796565
AL = 2500 non-productive time
ST = NT(1+Allowance) = 2237(125)=2797 minutes
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Example 2Time Study Example Problem
bull You want to determine the standard time for a job The employee selected for the time study has produced 20 units of product in an 8 hour day Your observations made the employee nervous and you estimate that the employee worked about 10 percent faster than what is a normal pace for the job Allowances for the job represent 25 percent of the normal time
bull Question What are the normal and standard times for this job
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Example 2Time Study Example Solution MOD
If ST=tiL(1+p) then STL=ti(1+p) ST = Time worked (min)
L Number of units produced = (480 minutes20) x (110) = 264 minutesbull 10 faster is a 110 performance rating
usually stated as 110Standard time = NT (1+025) =264 NT = (264)(1+025) = 2112 minutes
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Example 3Time Study ApproachIn a time study of a manufacturing
operation the average time observed to complete a product was 86 minutes The performance rating applied to the observed worker was 095 and the allowance during an 8-hour shift was 125 or 60 minutes
Compute the labor standard
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Example 3 Time Study Approach
bull Observed time = 86 minutesbull Performance rating = 095bull Allowance fraction = 0125bull Normal time = Observed time x Performance rating
= 86 x 095 = 817 minutes
bull Standard Time = Normal time (1 - Allowance) = 817 (1 - 125) = 817 (0875)
= 9337 minutes
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Example 4Time Study Example
bull Job elementsndash Pick up piece and place in jigndash Tighten set screw from jigndash Clean out chipsndash Advance drill to workndash Drill 14rdquo holendash Raise drill from holendash Loose set screwndash Remove piece
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Example 4Time Study Example
Trial 1 2 3 4 5 6 7 8 Rating1 012 013 005 57 004 006 008 013 1182 011 012 004 054 003 006 009 010 1093 012 012 004 056 003 007 008 012 1144 013 014 004 051 003 006 008 014 1235 012 011 005 054 003 006 009 013 1236 010 012 004 058 003 006 008 012 1137 012 012 004 052 003 006 007 013 1098 012 013 004 053 003 006 008 012 1119 014 012 003 059 004 007 009 012 120
10 012 011 004 056 003 008 007 011 112Avg 012 012 004 055 003 006 008 012 110
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Example 4Time Study Example
bull Normal Timendash Total Average Observed Time = 112 minndash Average Performance Rating = 110ndash Normal Time = (112 min)(110) = 123 min
bull Standard Timendash Total allowances = 14ndash Standard Time = (123 min)(1- 014) = 143 min
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Example 5Time Study Example
bull A new hire finishes 8 complete units during her 480 minute shift Assuming ST = 5207 and the allowance is 25 how proficient is this workerndash We expect a typical worker to make 480 min(521minunit) or about 92
units in a shift She made 8 which is less than the standard indicatesndash Compared with a standard worker her proficiency is 892 or about 86
bull We need to build 125 more units this shift which ends in 4 hours How many workers are needed to achieve this objectivendash If each unit takes 521 minutes of labor we need a total of 125 x 521 =
6512 minutes ndash By the end of the shift each worker will contribute 4 hours 240 minutes
Thus we need 6512240 = 2713 workers
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Example 6
bull NT = 88 min 35 extra for cleaning part Allowances = 4 + 5 + 35 (extra) = 125 Standard time = 88 + 88times(125) = 99 or more simply = 88times(1125) = 99
bull Discuss where do we get 4 and 5
bull Relaxation allowances taken as rest breaks 1) 30 min lunch 2) two 10-min breaks 3) Better to give a worker frequent short micro-pauses
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Figure 175Figure 175
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Performing a Time StudyTime Study Observation Sheet
Identification of operation Sandwich Assembly Date 517
Operator Approval ObserverSmith Jones Russell
Cycles Summary
1 2 3 4 5 6 7 8 9 10 t NtRFt
Place ham cheese and lettuce on bread
1
2
3
4
Grasp and lay out bread slices
Spread mayonnaiseon both slices
Place top on sandwichSlice and stack
t
t
t
t
R
R
R
R
11 44 79 113 147 183 221 260 298 337
04 05 05 04 06 05 06 06 07 05 53 053 105 056
04 38 72 105 140 176 213 250 289 329
07 06 07 08 08 0807 07 10 09 77 077 077100
1112 14 12 12131313 14 14 128 128 110 141
9323 55 125 160 196 234 272 312 351
1210 08 09 12 1011 11 1010 103 103 110 113
33 67 101 134 171 207 244 282 324 361
Example 173Example 173
Normal time = (Elemental average)(rating factor)
Nt = ( t )(RF) = (0053)(105) = 0056
Normal Cycle Time = NT = Nt = 0387
ST = (NT) (1 + AF) = (0387)(1+015) = 0445 min
Average element time = t = = = 0053 t10
05310
How many sandwiches can be made in 2 hours
= 2697 or 270 sandwiches120 min
0445 minsandwich
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 10 minutes and whose performance rating is only 90
a 90 minutesb 9 minutesc 110 minutesd 11111 minutese None of the above
Answer b 9 minutes (10 x 090=9 minutes)
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Question BowlWhich of the following is the Normal Time
for a job whose observed performance time is 35 minutes and whose performance rating is 30 above normal time
a 40 minutesb 50 minutesc 60 minutesd 116666 minutese None of the above
Answer e None of the above (NT=35x(13)=455 minutes)
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Question BowlWhich of the following is the Standard
Time for a job whose Normal Time is 20 minutes and whose Allowances are 5 of Normal Time
a 1905 minutesb 21 minutesc 400 minutesd 450 minutese None of the above
Answer b 21 minutes (ST=NT(1+Allowances) or 20(105)=21 minutes)
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Time Study Normal Time Formulas
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
bull Normal time(NT)=Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas So a person working 10 faster than normal would have a Performance Rating of 110 or 110 of normal time Working 10 slower 090 or 90 of normal
bull NT= Time worked x (Performance rating)
Number of units produced
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Time Study Standard Time Formulas
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
bull Standard time = Normal time + (Allowances x Normal
times)
bull Standard time = NT(1 + Allowances)
bull Standard time = NT
1 - Allowances
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
The Standard Time
bull The sum of elemental times gives the standard in
minutes per piece using a decimal minute watch
or hour per piece using a decimal hour watch
bull Most of industrial operations have short cycles
(lt 5 min)
bull Better express standard in hours per hundred
pieces
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Pay-for-Performancebull Paying employees based on their
performance works--improvements in productivity and quality
bull Pay-for-performance will become increasingly common components of performance management strategies and systems
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Compensation Methods
bull Some reasons a company might use a wage incentive planndash Increased pay for employeesndash Lower total cost to the company for each unit
produced
bull Many jobs do not lend themselves to an individual incentive plan
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Wage Incentive Plans
bull Piecework plansbull Standard hour wage plansbull Gain-sharing plansbull Recommendations for developing and implementing
successful wage incentive plansndash The plan should permit earnings about the base rate good
performance should pay at least a 30 bonusndash The plan should benefit both the company and the employeesndash The plan should be simple and understandablendash The standards should be protected from capricious and
indiscriminate rate cuttingndash Earnings should not be affected by factors beyond the control of
the worker
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
Group Incentive Plans
bull Direct-wage groupbull Profit-sharing and cost-reduction plansbull The Scanlon plan
ndash Whenever a plant-s productivity exceeds a preestablished ldquonormalrdquo level every employee gets a bonus - the higher the level of productivity the bigger the bonus
ndash The plan also involves a style of management designed to give each worker some control over his or her job by encouraging participation in decision making affecting it
ndash Productivity is increased by a well-designed employee suggestion plan and through the use of special committee that constantly prod employees for ideas on how to improve productivity
