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WELCOME TO THE

COURSE

WORK STUDY(IE 341)OFFERED BY

SAYED ALIUL HASAN RIZVI, PhD

PROFESSOR

DEPT OF INDUSTRIALENGINEERING

KING ABDULAZIZ UNIVERSITY, JEDDAH

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INTRODUCTION

With increasing complexities of thetechnological world,need to simplify the work

system has been increasing day by day.

Work study is an area of knowledge thataddresses the problem of work simplification

with the basic objectives of

1. PRODUCTIVITY ENHANCEMENT, and

2. HUMAN COMFORT & SAFETY

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WORK STYDY HAS MANY OTHER NAMES

FOR EXAMPLE

METHODS ENGINEERING,WORK SCIENCE,

WORK DESIGN,

JOB ESIGNWORK METHODS DESIGN &WORK

MEASUREMENT

MOTION &TIME STUDY

Original names were:Motion study,Time Study

& then, Motion & Time Study

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DEFINITION

It is the systematic study of work systems with thepurposes of

1. Developing the preferred system and Method

( with lowest cost)

2. Standardizing this system and method

3. Determining standard time for the task

4. Assisting in training the workerin thepreferred Method

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EXPLANATION

Above stated definition has FOUR parts.

However, the TWO most important for WORK

STUDY are:

1.MOTION STUDY

(or Work Methods Design) &2. TIME STUDY

(or Work Measurement)

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ILO DEFINITION

It is the systematic examination of

carrying on activities so as toimprove the effective use ofresources and to set standards of

performance for the activities beingcarried out.

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LECTURE : 3-4

CHAPTER : 2

WORK STUDY & PRODUCTIVITY

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HUMANS BASIC NEEDS & PRODUCTIVITY

In 1950: world population was 2.5 b

Now : it is of the order of6.5 b

90% increase has occurred indeveloping nations.

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CONTD.

Out of these people, more than

1 b arebelow poverty line, strugglingfor the

BASIC NEEDS which are :

food,

clothing,

shelter, security,

health and

essentials like water, sanitation etc.

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CONTD.

For Improving the STANDARD OF LIVING, of its

citizens, the concerned nation must raise its

PRODUCTIVITY for economic growth. For any

organization, its input-output system can be

represented as follows:

INPUT OUTPUT

PROCESS

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CONTD.

INPUTSmay be in the form of different Ms:

man, material, machine, method,

management, market, message ( i.e.

information), moment (i.e. time )

OUTPUTmay be a

product or

service.

PRODUCTIVITY may be defined as follows:

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MATHEMATICALLY:PRODUCTIVITY = [OUTPUT / INPUT]

THUS:

PRODUCTIVITY measures the extent to which acertain OUTPUT can be extracted FROM A

GIVEN INPUT.

It may be noted that PRODUCTION ( which is

number of products) is different from

PRODUCTIVITY.

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CONTD.

WORK STUDY IS A TOOL OF

PRODUCTIVITY ENHANCEMENT.

It simplifies a job

TO REDUCEUNNECESSARY OR EXCESSWORK,

WASTEFUL USE OF RESOURCESand sets up STANDARD TIME forperforming that job.

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CONTD.

THIS IMPLIES THAT :

THERE IS A DIRECT

RELATIONSHIP BETWEEN WORK

STUDY AND PRODUCTIVITY. THUS, BY APPLYING WS

PRINCIPLES IF THE COST ISREDUCED BY 20%, THEN, WE CAN

SAY THAT PRODUCTIVITY HAS

GONE UP BY 20%.

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WORK CONTENT OF A JOB

WORK CONTENT

It means the amount of work contained in a

given job/work/product/process.

It is measured inMAN-HOURS/ WORK-

HOURS (effort or labor of ONE person for ONE

hour), orMACHINE HOURS (running of a

machine/plant for ONE hour).

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TOTAL TIME OF A JOB

TOTAL TIME OFA JOB COMPRISES OF:

1. BASIC WORK CONTENT &

2. EXCESS WORK CONTENT

BASIC WORK CONTENT is irreducible minimum time

required theoretically to produce one unit of product

In REAL LIFE WORLD, actual operation times are

FAR MORE IN EXCESS due to the EXCESS WORK

CONTENT.

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CONTD.

EXCESS WORK CONTENT may be due

to followingTHREE CATEGORIES of factors:

(i) A-category:

A1: POOR DESIGN & FREQUENT

DESIGN CHANGESA2: WASTE OF MATERIALSA3: INAPPROPRIATE QUALITY

STANDARDS

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CONTD.

(ii) B-categoryB1: POOR LAYOUT & POOR

UTILISATION OF SPACE

B2: INADEQUATE MATERIALHANDLING

B3: FREQUENT STOPPAGES AS

PRODUCTION CHANGES FROM

ONE PRODUCT TO ANOTHER

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CONTD.

B4: INEFFECTIVE METHOD OFWORK

B5: POOR PLANNING OF

INVENTORY

B6: FREQUENT BREAKDOWN

OF MACHINES ANDEQUIPMENT

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iii) C-category

C1: ABSENTEEISM AND LATENESS

C2: POOR WORKMANSHIP, ANDC3: ACCIDENTS AND OCCUPATIONAL

HAZARDS

= BASIC WORK CONTENT + EXCESS WORK CONTENT ( A + B +C )

(OR, TOTAL INEFFECTIVE TIME)

TOTAL TIME OF A JOB

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LECTURE : 5-8

CHAPTER : 3

WORK STUDY ,THE APPROACH:

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WS IS VALUABLE because

By carrying out its systematic

procedures,one can get results as

good as or even better than the less

systematic genius would have beenable to achieve in the past.

It is systematic both in theinvestigation of the problem and in

the development of its solution.

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CONTD.

It contributes to human safety byproviding safer methods of work, and

allows for better working conditions by

exposing the hazardous situations.

Its application starts providing savings

immediately, and continues till theoperation continues.

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CONTD.

It is a tool that can be used every where, be it

industrial or non-industrial environment.

It is easy and relatively cheaper in its

application.

It is an excellent weapon for starting an

attack on the inefficient system.

HOWEVER, WS SPECIALISTS SHOULD APPLY ITTACTFULLY, SO THAT WORKERS REMAIN CO-

OPERATIVE WHILE STUDIES ARE CONDUCTED IN

THE PLANT.

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TECHNIQUES OF WORK STUDY:

These are:

1. METHOD STUDY is the systematic recording andcritical examination of ways of doing things in

order to make improvements.

THUS it simplifies the job and develops more

economical method of doing it.

2.WORK MEASUREMENT is the application

of techniques designed to establish the time for a

qualified worker to carry out a task at a defined rate

of working.

THUS it determines how long it should take to

carry out the work.

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BASIC PROCEDURE OF WScomprise of followingSTEPS:

1.SELECT the job/task/process to be studied.2.RECORD all the relevant data/facts about the

selected job.

3.EXAMINE the recorded facts critically by challenging

its purpose, place, sequence, person, and

method.

4.DEVELOP new methods,as alternative methods, of

doing the selected job.

5.EVALUATE results of different alternative solutions.

6.DEFINE the new method and present it to theconcerned people.

7.INSTAL the new method and provide training to

the concerned staff .

8.MAINTAIN the new standard practice and establishcontrol procedures.

ACCORDING TO BARNES

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ACCORDING TO BARNES:Since Methods Engineering is a form ofCREATIVEPROBLEM SOLVING, THE GENERAL PROBLEM SOLVINGPROCESSES can be employed in WS also. Accordingly,following FIVE STEPS can be used:

1.Problem definition : Statement of the purpose/goal

2. Analysis of the problem : Fact-recording no evaluation

3.Search for possible solutions : Finding severalalternative solutions.

4. Evaluation of alternatives : Examining whichalternative meets the goal/criteria most, inorder to evolve the preferred solution. &

5. Recommendationfor action: Communicating thedetails ,related to the preferred method to all concerned.

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LECTURE : 9-10

CHAPTER : 6

METHOD STUDY & JOB SELECTION

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STEP I : JOB/TASK/PROCESS SELECTION

It involves following considerations:

1. ECONOMIC CONSIDERATIONS

2. TECHNOLOGICAL

CONSIDERATIONS and

3. HUMAN CONSIDERATIONS

C td

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Contd.

1.ECONOMIC CONSIDERATIONS

Cost effectiveness i.e. to check whether ornot the WS application would pay. For this,

key-profit giving/ costliest operations with

largest waste/scrap should be attacked first.Next bottleneck operations, repetitive

operations, repeated material handling

operations should be studied. For locatingmost important operations, PARETO

ANALYSIS could be used.

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2.TECHNICAL/TECHNOLOGICAL

CONSIDERATIONS

The analysis involves application

of WS for the selection of theoperations/processes where new

technology e.g. automation/

robotisation should be introduced.

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3.HUMAN CONSIDERATIONS

Analysis involves location of those

operations which present the

sources of dissatisfaction and/or

annoyance to the workers due to

fatigue or monotony or unsafeenvironment or a work which is

clumsy in nature.

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LECTURE : 11-12

CHAPTER : 7

RECORDING THE FACTS :

DIAGRAMS & CHARTS

STEP II RECORDING THE FACTS

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STEP II : RECORDING THE FACTS

Related to the existing process/ job ALL THE FACTS should

be recorded ACCURATELY.

TOOLS OF FACT-RECORDING are:

(A) CHARTS,which may be oftwo types:

(i) Based on SEQUENCE:

(a) Outline Process Chart

(b) Flow Process Chart(c) Two-Handed Chart ( or Operation

Chart / Left Hand & Right Hand chart)

CONTD

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CONTD.

(ii ) Based on TIME scale:

(a) Multiple Activity Chart

(b) SIMO ( SImultaneous MOtion) Chart

(B) DIAGRAMS: which may be of the

following types:

Flow diagram,String Diagram, Travel Chart,

Cyclegraph, & Chronocyclegraph,

PROCESS CHART SYMBOLS

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PROCESS CHART SYMBOLS

ASME has recommended FIVE standard symbols to be used on

Process Charts, given below:

1. OPERATION :Main steps of thetask /job involving modification /change.

2. INSPECTION: Checking quality / quantity.

3. TRANSPORTATION : For movement of

persons/materials.

4. DELAY (TEMPORARY) : For waiting time of

operators or materials.

5. STORAGE (PERMANENT DELAY)] : For

controlled storage involving authorizedissue/receipt of material etc.

NOTE:FOR TWO PARALLEL EVENTS, BOTH ARESHOWN IN ONE JOINT OR COMBINED SYMBOL: e. g.

operation & inspection ,jointly are shown

by symbol, indicated in the figure.

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THE OUTLINE FLOW PROCESS

CHART

It uses ONLY TWO SYMBOLS:

&

It provides an OVERALL PICTURE of theprocess / job / task.

Primarily it is used to show the sequence of

operations & inspections for a

MANUFACTURING or an ASSEMBLY kind of

jobs.

FLOW PROCESSCHART

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FLOW PROCESSCHART It uses ALL THE FIVE SYMBOLS and provides the

total sum details of the process/job under study. A Flow Process chart may be of the following

types:

1.MAN-TYPE in which every symbol is

related to his/her activity only.2.MATERIAL TYPE in which every symbol

is related to the material of the job

or a document (e.g. in offices) or amachine/equipment.

Data / information in a flow process chart arerecorded in specifically designed FORM, as given

in the TEXT BOOK / CLASS ROOM.

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LECTURE : 13-14

CHAPTER : 7 (CONTD)

STEP III : CRITICAL EXAMINATION

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STEP III : CRITICAL EXAMINATION

The facts recorded in the Flow ProcessChart are now EXAMINED CRITICALLY

by applying the

QUESTIONING TECHNIQUE,

which involves the followingSEQUENCE:

CONTD

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CONTD.

PURPOSE for which the activity is done

PLACE at ,, ,, ,, ,, ,, SEQUENCE in ,, ,, ,, ,, ,,

PERSON by whom ,, ,, ,, ,, ,,

MEANS by which ,, ,, ,, ,, ,,WITH THE OBJECTIVE OF ELIMINATING/

COMBINING/ REARRANGING/ SIMPLIFYING

THE ACTIVITIES INVOLVED IN THE PROCESS.

QUESTIONING TECHNIQUEinvolves

1. PRIMARY QUESTIONS and

2. SECONDARY QUESTIONS explained below:

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PRIMARY QUESTIONSAccording to the QUESTIONING TECHNIQUE the PRIMARY

QUESTIONS are as follows: Purpose-based: WHAT is actually done?

WHY is the activity ELIMINATEnecessary, at all?

Place-based: WHERE is it being done?WHY at this place?

Sequence-based: WHEN is it done?

WHY at that time? COMBINE or

Person-based: WHO is doing it ? REARRANGEWHY by this person?

Means-based: HOW is it being done? SIMPLIFYWHY in that particular way?

SECONDARY QUESTIONS

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SECONDARY QUESTIONS

Corresponding to each answer

obtained through the PRIMARYQUESTIONS further questions areraised to explore about the

ALTERNATIVES

i. e. alternate purpose, place,sequence, person & means.

This methodology makes use of theSECONDARY QUESTIONS given

as follows:

Contd

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Contd. WHAT ELSE might be done?

WHERE ELSE might it be done? WHEN ELSE might it be done?

WHO ELSE might do it? &

HOW ELSE might it be done?

BY ANSWERING THE PRIMARY &

SECONDARY QUESTIONS WE USE THE

SYSTEMATIC CRITICAL EXAMINATION IN

ORDER TO EVOLVE A BETTER METHOD OF

DOING THE WORK.

Contd

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Contd.

AS A RESULT, ONE CAN DEVELOP ABETTER METHOD IN LIGHT OF THE

OBTAINED ANSWERS TO THE FOLLOWING

QUESTIONS:

WHAT should be done?

WHERE should it be done? WHEN should it be done?

WHO should do it ?

HOW should it be done?

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LECTURE : 15-17

CHAPTER : 8

RECORDING MOVEMENT OF

WORKERS/MATERIALS

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RECORDINGMOVEMENT OF WORKERS/

MATERIALS

TOOLS USED FOR THIS PURPOSE ARE:

STRING DIAGRAM

FLOW DIAGRAM

TRAVEL CHART

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STRING DIAGRAM

IT IS A SCALE PLAN OR MODEL ON WHICH

A THREAD OR STRING IS USED TO TRACE

AND MEASURE THE PATH OF WORKERS/MATERIALS DURING A SPECIFIED

SEQUENCE OF EVENTS.

LENGTH OF THE THREAD/STRINGMEASURES THE DISTANCE MOVED.

FLOW DIAGRAM

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FLOW DIAGRAM

It is a FLOOR-PLAN showing the path of

travel of the operator or the material,

through the plant.

It ALSO indicates the direction of travel by

means ofarrows, drawn on the diagram.

TRAVEL CHART ( or FROM TO CHART)

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TRAVEL CHART ( or, FROM-TO CHART)

It is a tabular record of quantitative data about

movement of workers/materials/equipment betweenany number of places over a given period of time. It is

always in the form of a SQUIRE, having within it the

squires.

EACH SMALL SQUIRE REPRESENTS A STATION.Along the TOP, squires from left to right represent the

stations FROM where movement or travel occurs.

Along those DOWN THE LEFT HAND, the squiresrepresent the stations TO which the movement is

made.

MAN-MACHINE CHART

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MAN MACHINE CHART

(MULTIPLE ACTIVITY CHART)

This kind of process chart records the activities ofthe operator as well as the machine on the samechart against a common time scale.

Separate vertical columns ( in the form of bars)are used for both.

The chart clearly indicates the IDLENESS (orUTILISATION) of operator as well as the machine.

On the basis of the recorded events in the chart,one can rearrange the process so that IDLE-TIME

is reduced, orBETTER UTILISATION of theoperator/machine is achieved.

It is used for balancing the work between manand machine ;proper utilization of maintenancecrew /team-activities in mass production.

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LECTURE : 18-24

CHAPTER : 9

METHODS & MOVEMENTS AT THE

WORKPLACE

METHODS & MOVEMENTS AT THE

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METHODS & MOVEMENTS AT THE

WORKPLACE

PRINCIPLES OF MOTION ECONOMY

These principles can be helpful in work design, inreducing the human fatigue and in improving thework efficiency. According to Barnes, these can bepresented under following THREE subgroups:

1.Principles of motion economy as related to theUSE OF HUMAN BODY

2.Principles of motion economy as related to the

ARRANGEMENT OF THE WORKPLACE

3.Principles of motion economy as related to theDESIGN OF TOOLS & EQUIPMENT

[A] .Principles of motion economy as related to

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y

the USE OF HUMAN BODY

1.The two hands should begin and

complete their movements at the sametime.

2. The two hands should not be idle at the

same time. 3.Motions of the arms should be

symmetrical and in opposite direction

and should be made simultaneously.

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Principles:Contd

4.Hand and body motions should be made at

the lowest classification at which it is possible

to do the work satisfactorily.

[The term CLASSIFICATION OF HAND

MOTION is explained as follows]

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CLASSIFICATION OF HAND MOTIONS

CLASS PIVOT BODY MEMBERS MOVED

1 Knuckle Finger (F)2 Wrist Hand (H) + F

3 Elbow Fore Arm (FA) + H + F

4 Shoulder Upper Arm (UA) +FA+H+F5 Trunk Torso + UA + FA + H + F

Principles : CONTD

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Principles : CONTD. 5. Momentum should be employed to help the

worker ,but should be reduced to a minimumwhenever it is to overcome by muscular effort.

6.Continuous curved motions are to bepreferred to straight line motion involving

sudden and sharp changes in direction.

7. Ballistic (free-swinging) motions are

faster, easier, and more accurate than

restricted or controlled motions.

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PrinciplesCONTD.

8.Rhythm is essential to the smooth and

automatic performance of a repetitive operation.

The work should be arranged to permit an easy

and natural rhythm whenever it is possible.

9.Work should be arranged so thateye-

movements are confined to a comfortable

area, without the need for frequent changes ofthe focus.

[B] Principles of motion economy as related

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[B].Principles of motion economy as related

to the ARRANGEMENT OF THE WORKPLACE

1.Definite and fixed positions/stations

should be provided for all tools and

materials to permit habit formation.

2.Tools and materials should be pre-

positioned to reduce searching.

CONTD

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CONTD.

3.Gravity-feed, bins and containers shouldbe used to deliver the materials as close tothe point of use as possible.

4.Tools, materials, and controls should belocated within the maximum working areaand as near to the worker as possible.

[WORKING AREA (WA) may be divided into:

1.NORMAL WA &

2.MAXIMUM WA explained below ]

Cotd.Normal Working Area (WA) :

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( Finger + wrist + elbow) Movement

MOST CONVENIENT ZONE

Edge

of bench operator

operator

Maximum WA : (Shoulder Movement)

DIMENSIONS FOR SEATED TASKS

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DIMENSIONS FOR SEATED TASKS

1.SEAT HEIGHT should be adjustable :

( range:36-45 ) 2. WORK SURFACE HEIGHT should be around

elbow level (range:65-72 cm)

3.LEG CLEARANCE : 40 cm at knee level

& 60 cm for the feet

4.THIGH CLEARANCE : 20 cm minimum

5.WORK SURFACE THICKNESS : 5cm max.

P i i l CONTD

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Principles : CONTD. 5.Materials and tools should be arranged to

permit the best sequence of motions.

6.Drop deliveries or ejectors should be

used wherever possible, so that operatorsdo not have to use his/her hands to dispose

of the finished work.

Principles: CONTD.

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p

7.Provision should be made for adequate

lighting and, a chair of the type of height topermit good posture should be provided.

The height of the workplace and seat should

be arranged to allow alternate standing and

sitting.

8.The color of the workplace shouldcontrast with that of the work and thus

reduce the eye-fatigue.

[C]. Principles of motion economy as related to thethe DESIGN OF TOOLS & EQUIPMENT

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the DESIGN OF TOOLS & EQUIPMENT

1.The hands should be relieved of all work

of holding the work-piece where this canbe done by a jig, fixture or foot-operated

device.

2.Two or more tools should be combinedwherever possible.

3.Where each finger performs some specific

movement, as in typewriting, the load shouldbe distributed in accordance with the

inherent capacities of the fingers.

Principles : CONTD

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Principles : CONTD. 4.Handles such as those on cranks and large

screw divers should be so designed that asmuch surface of the hand as possible can come

in contact with the handle. This is specially

necessary when considerable force has to be

used on the handle.

5.Levers crossbars and hand-wheels should beso placed that the operator can use them with

the least change in body position and the

largest mechanical advantage.

TWO-HANDED PROCESS CHART (OPERATION

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CHART/LEFT-HAND RIGHT-HAND CHART)

It shows the activities of the two hands in

relation to one another.ACCORDING TO BARNES:

It uses ONLY TWO SYMBOLS: &

Small circle for TRANSPORTATION& Big circle for OPERATION.

ACCORDING TO ILO :

It uses ALL process chart symbols EXCEPTINSPECTION

After studying a few cycles recording is done.

ONLY ONE HAND is charted AT A TIME.

FUNDAMENTAL HAND MOTIONS

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FUNDAMENTAL HAND MOTIONS

Gilbreth observed that most work doneby two hands consists of a few

fundamental motions.

He called EACH ONE of them as

THERBLIG. (name of GILBRETH ,read in

reverse order).

THERBLIG : G I L B R E T H

( read in reverse order)

contd.

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Today we have 17 Therbligs as follows:

Search, select, grasp,

transport empty, transport loaded,

hold, release load position,

preposition, inspect, assemble,

disassemble, use, unavoidable delayavoidable delay, plan, &

rest for overcoming fatigue.

THESE ARE USED IN MICROMOTIONSTUDIES (FACTS RECORDED ON FILMS)

MICROMOTION STUDIES

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Operations with very short cycles &

repetitive cycles need greater details toanalyze it for saving motions and effort(

i.e. planning for lesser fatigue). This goal

can be achieved through Micro-motion

Studies.

MICRO means small. Thus here we

study the motions in terms of

THERBLIGS.

CONTD.

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Such a study involves the use of

FILM and VIDEO

when operator performs the job.

Later on the film/video can be run slowlyTHROUGH A PROJECTOR and

Frame by frame analysis of the work

can be carried out.

Film provides greater flexibility of filming

and playback speeds WHEREAS video is

easier in use.

Contd.

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STEPS:

1. Filming the job

2. Analysis of the film, &

3. Presenting DATA/FACTS

graphically throughSIMO chart.

(SImultaneous Motion Chart)

CONTD

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CONTD.

EQUIPMENT:

Camera, Film, Micro-chronometer,Exposure meter, Flood lights,

Reflectors, Tripod,, Projector etc.

OR,

VIDEOCAMERA plus itsaccessories for filming

operation.

CONTD.

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ADVANTAGES OF MICROMOTION STUDIES

OVER DIRECT OBSERVATION.

Greater details are made availalble

More accurate

Easier in data collection

Better for record keeping Help in work study personnel's

development FILM ANALYSIS:

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Film is run on projector,

Details of the work-cycle are identified interms of THERBLIGS, first for

Left hand

and then forRight hand,

TIME ( in WINK) is noted from the

Chronometerreadings of the film for eachtherblig.

[1 WINK = (1/2000) OF A MINUTE ]

CONTD.

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With these data SIMO (Simultaneous

Motion) chart is made as shownbelow :

LH Activities Therblig Time Therblig RH Activity

MEMOMOTION ANALYSIS

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It was introduced by MUNDEL.

It is a special type of micro-motion study inwhich activities are FILMED AT MUCH

SLOWER SPEED (60 to 100 frames per

minute) i.e. at longer intervals than normal(intervals being between 0.5 to 4 s).

Thus a general pattern of movements can

be obtained and avoidable motions can beidentified.

contd.

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STEPS: Study the operation to be filmed ;

Prepare the film ; Analyze the film ;

Develop a better method.

ADVANTAGES: More economical (less film

consumed) and Long sequence of activities can be

recorded; APPLICATIONS:

Team-work studies ;

Material flow studies ( e.g. baggagemovement at the airports)

Long cycle job studies &

Study of artificial limbs motions etc

CYCLEGRAPH

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It was introduced by Gilbreth.

It is a photographic record of the path of

movement of the operator doing a job.

Little source oflight (bulb) is attached to the

hand or finger or any other body part, whose

motions are to be analyzed. When he/sheperforms the operation and photograph is

taken continuously, the path of motions is

recorded on the film as CONTINUOUS

STREAK OF LIGHT as shown below

OPERATO R

CHRONOCYCLEGRAPH

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It is a special type of cycle-graph in which the lightsource (bulb) is suitably INTERRUPTED ELECTRICALLYso that the path of motion in the photograph appears as

a SERIES OF PEAR-SHAPED SPOTS instead ofcontinuous streak of light as shown below

PEAR-SHAPED SPOTS

MOTION DIRECTION

The pointed end of the pearshows the direction of movement.

More elongated and spaced pear-spots indicate higher speed ofoperation..