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    BITSPilaniPilani Campus

    Manufacturing Organization

    and Management

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    Methods EngineeringLecture 10

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    BITS Pilani, Pilani Campus

    Method engineering is that body of knowledge

    concerned with the analysis of the methods and

    equipment used in performing a job, the design of an

    optimum method, and the standardization of the

    proposed methods. This field is frequently referred to as:

    Motion Study

    Method Design

    Operation Analysis Work Study

    Job Design

    It is closely affiliated with the function of work

    measurementor timestudy.

    Introduction

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    The application of methods engineering may be required

    in a variety of circumstances.

    It ranges

    From the design of a new plant,

    To the design of a new product,

    To the design of a new process,

    To the improvement of an existing process,

    To the improvement of an existing workplace.

    Wherever work is being done, methods engineering is adesirable function to ensure that the work is being done

    in the easiest, safest, and most productive way.

    Areas of Application

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    Example:

    The time to install phenolic fuse holder in an electronic

    chassis is reduced 70%.

    50% reduction in production cost resulted from a

    revolving assembly line linked with a new welding

    technique. 90% reduction in down time.

    A switch from wooden to corrugated packaging reduced

    labor, material, shipping cost.

    Method design and method improvement is one of the

    best avenues to manufacturing cost reduction and

    increased productivity.

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    Methods engineering grew out of the pioneeringdevelopments of the Gilbreth who developed many ofthe tools of motion study as a part of formulation asystematic approach to the analysis of work methods.

    Gilbreth, who in 1885 was employed as an apprentice

    bricklayer, soon observed that a journeyman bricklayerused one set of motions when laying bricks slowly,another set when working at average speed, and still adifferent set when working at rapid speed.

    As a result of his observations, he invented anadjustable scaffold and developed a set of motions thatgreatly increased the number of bricks that could be laidin a day.

    Origin of Methods Engineering

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    As indicated previously, methods engineering is a

    necessary function to ensure that the most efficient

    methods are being used.

    This activity is most frequently performed by industrial

    engineers; however, all engineers should be concernedwith work methods.

    The engineers may be assigned to a central methods

    engineering or industrial engineering department or may

    be assigned on a decentralized basis to specificoperating departments.

    Organization for Methods

    Engineering

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    Some multi-plant companies maintain both a central

    industrial engineering group to work on problems

    common to many plants and also assign engineers to

    each plant to work on projects pertinent only to that

    plant.Method engineering may be either beforethe factor

    afterthe fact. Thatmeans it may consist of designing

    a new process or system not previously used in the

    organization or it may consist of the improvement of anexisting process or work place.

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    To determine how much engineering time and effort can

    be justified on a methods project, following factors can

    be taken into account:

    The volume of production to be scheduled on the job

    The anticipated life of the job The current investment in machines, tools and equipments

    The personnel considerations.

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    Charles E. Geisel States that in order to design a system(method) thoroughly, eight elements must beconsidered.

    1. Purpose: The function, mission, aim or need for thesystem.

    2. Input: The physical items, people, and/or informationthat enter the system to be processed into the output.

    3. Output:That which the system produces to accomplishits purpose, such as finished steel, assembled toasters,boxes, and so forth.

    4. Sequence:The steps required to convert, transform, orprocess the input to the output.

    Approach to Methods Design

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    5. Environment: The condition under which the systemoperates, including physical, attitudinal, organizational,contractual, cultural, political, and legal environment.

    6. Human agents: The people who aid in the steps of thesequence without becoming a part of the output.

    7. Physical catalysts: The equipment and physicalresources that aid in the steps of the sequence withoutbecoming part of the output.

    8. Information aids: Knowledge and information resources

    that aid in the steps of the sequence without becomingpart of the output.

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    To ensure that the optimum method is found, asystematic approach to methods design, superior to theuse of a hitor missmethod, is used. Stated in simplestform, this approachconsists of the following steps:

    1. Analyze the problem: Identify the problem and then secure all

    known information about it through the use of appropriate analysistechniques.

    2. Question the present method: If a method presently exists,question the details of the known information to determine theprinciples violated.

    3. Synthesize a proposed method: Formulate a proposed methodfor performing the work, embodying all the principles of soundmethods engineering.

    4. Apply the proposed method: Standardize and apply the newmethod.

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    Tools for Methods Analysis

    A number of charting techniques have beendeveloped which are very useful in analyzing

    work methods.

    These charts are of value in studying both

    macro and micro motionsand a classificationof them.

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    Name of Chart Where Used

    Flow Process Macro analysis; shows big picture of a

    production process operation by

    operation; may be performed by visual

    observation.

    Operation right

    and left-hand

    Micro analysis: Shows steps performed

    by a worker within an operation; may

    be performed by visual observation.

    Charting Techniques

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    Simo-simultaneous

    motion chart

    Fine micro analysis; uses THREBLIGSfor a very detailed analysis of human

    motions; usually makes use of

    videotape or motion pictures.

    Multiple activity

    worker and

    machine or crew

    Macro; may involve machines or

    several workers and time is of

    significance, may be performed byvisual observation and/or videotape.

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    In analyzing the movement of a product, person, orpaperwork, the flow process chart is invaluable inproviding a graphical representation of the step-by-stepsequence that takes place.

    A flow process chart is a graphic symbolic representationof the work performed or to be performed on a productas it passes through some or all of the stages of aprocess.

    Typically, the information included in the charts is

    quantity, distance moved, type of work done by symbolwith explanation, and equipment used. Work times mayalso be included.

    Process Chart

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    Symbols used for process charting

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    It shows that it outlinesVarious operations

    Transportations

    InspectionsDelays

    Storages

    Flow process chart

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    Flow process chart

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    Typical questions that may be raised about each of thesteps on a process chart include the following:

    1. Can an operation eliminated?

    2. Can an operation be combined with another operation?

    3. Can the production sequence be changed?

    4. Can an operation or inspection be simplified?

    5. Can a movement be eliminated or shortened?

    6. Can a delay or storage be eliminated?7. Can this step be eliminated by redesigning the product

    or using different material?

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    Typical questions that may be raised about each of thesteps on an operation chartinclude the following:

    1. Can a sub-operation be eliminated or combined?

    2. Can a transportation process be eliminated or

    shortened?

    3. Can the sequence or motions be changed to facilitate

    the operations?

    4. Can a delay be eliminated?

    5. Can a hold be eliminated through the use of a jig or

    fixture?

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    In those operations involving the combination of apersonand a machine, a person and several machines,or any combination of people and machines wheredelays are prevalent, the multiple activity chart providesa convenient technique for analyzing the combined

    activity. Very often the objectives of this type of analysis are to

    attain the maximum utilization of a machine, to attain theoptimum person to machine relationship, or to bringabout the best balance of crew activity.

    For this reason, the time factor is an importantconsideration and necessitates the use of a graphicalrepresentation involving time.

    Multiple Activity Chart

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    There are many situations in which it is difficult to observe all of theaction taking place because of the high speed of activities or thecomplexity of the operation.

    Having observed slow-motion motion pictures, we are familiar withthe fact that one can take motion pictures at high speed and then, byprojecting them at normal speed, slow the action down.

    By the same token, we can take the pictures at slow speed andproject them at what appears to be high speed.

    In using motion pictures, methods engineers may have had severalobjectives in mind.

    First and foremost, they may have wanted a permanent record of

    the work as it was being performed. Or they may have wished to usethe film for analysis purposes, commonly referred to asmicromotionor memomotionstudies, discussed in some detail insections that follow.

    Use of Videotape

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    A recent innovation has been to make use of videotapeinstead of motion picture.

    The development of improved and low cost equipment

    has made this technique increasingly attractive and is

    now used almost exclusively. Current camcorders have high speed shutters, zoom

    lenses, time lapse recording and provide the distinct

    advantages of instantaneous replay.

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    Micromotion study, which was originated by Frank B.Gilbreth, is one of the most exacting forms of workanalysis available for job improvement.

    It is an analysis technique making use of motion pictures(or videotape) taken at a constant and known speed.

    The film becomes a permanent record of both themethod being used and the time consumed in doing thework.

    Although micromotion study formerly made use ofmotion pictures, very few companies today are using

    them.As indicated earlier, videotape equipment has been

    developed so extensively that it has virtually supplantedthe use of the motion picture camera.

    Micromotion Study

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    Further it is so cheap and easy to use that it makes theolder approach archaic.

    It may be used to study the interrelationships among themembers of a work group, to study the relationshipbetween an operator and his machine to obtain the timefor an operation to establish a permanent record of a jobmethod and similar activities.

    Micromotion study provides a valuable technique formaking minute analyses of those operations that are shortin cycle, contain rapid movements, and involve highproduction over a long period of time.

    Thus it is very useful in analyzing operations such as thesewing of garments, assembly of small parts and similaractivities.

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    The usual procedure for preparing micromotion study is totake videotapes of the operations, analyze the resulting tape

    and prepare a SIMO (simultaneous motion cycle) chart from

    the results of the analysis.

    In analyzing the tape, very accurate time values may be

    obtained by reading a clock that appears in each frame of thetape.

    The tape is analyzed by breaking the cycle down into

    therbligsor basic body motions.

    Although the 17 therbligs are not the smallest subdivision intowhich human activity can be subdivided, they are widely

    known and can conveniently be applied.

    The following figure shows the therbligs with their symbols,

    colors, and interrelationship with operation chart symbols.

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    In analyzing the videotape, it is common practice firstto record the description on a film analysis sheet; from

    this information a SIMO chart may be prepared.

    Examination of the SIMO chart illustrated in figure 10-

    10 discloses that the simultaneous action of eitherhand may be determined by reading horizontally

    across the chart and that the duration of each

    therbligs is illustrated in the time column.

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    After preparation of simo chart, it should be studiedand subjected to question in order to find the better

    way of doing the work.

    Every attempt should be made to eliminate those

    therbligs that are nonproductive (hold, avoidable,delay, unavoidable, plan, rest, select, search) as

    well as shorten those that are productive.

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    Memomotion study, which was originated by M.E. Mundel, is aspecial form of micromotion study in which the motion pictures orvideotape are taken at slow speeds.

    Sixty and one hundred frames per minutes are most common.

    Memomotion study has been used to study the flow and handling ofmaterials, crew activities, multiperson-and-machine relationships,

    stockroom activities, department store clerks, and a variety of otherjobs.

    It is particularly valuable on long-cycle jobs or jobs involving manyinterrelationships.

    In addition to having all of the advantages of micromotion study, it

    can be used at relatively low film or tape cost (about 6% of the costat normal camera speeds) and permits rapid visual review of longsequence of activities.

    Memomotion Study

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    Principles of Motion Economy Through the pioneer workof Gilbreth, Ralph M. Barnes and other investigators,certain rules for motion economy and efficiency havebeen developed. Some of the more important of theseprinciples are the following:

    1. The movements of the two hands should be balancedand the two hands should begin and end their motionssimultaneously.

    2. The hands should be doing productive work and should

    not be idle at the same time except during rest periods.3. Motions of the hands should be made in opposite and

    symmetrical direction and at the same time.

    4. The work should be arranged to permit it to beperformed with an easy and natural rhythm.

    Principles of Motion Economy

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    5. Momentum and ballistic-type movements should be

    employed wherever possible in order to reduce musculareffort.

    6. There should be a definite location for all tools and materials,and they should be located in front of and close to theworker.

    7. Bins or other devices should be used to deliver the materialsclose to the point of use.

    8. The workplace should be designed to ensure adequateillumination, proper workplace height, and provision foralternate standing and sitting by the operator.

    9. Wherever possible, jigs, fixtures, or other mechanical devices

    should be used to relieve the hands of unnecessary work.10. Tools should be prepositioned wherever possible in order to

    facilitate grasping them.

    11. Object should be handled, and information recorded. Onlyonce.

    J b E l t d

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    This has led to the contention of a number of socialscientists that hobs need to be enlarged or enriched.Feedrick Herzberg, one proponent of job enrichment,feels that the purpose of job enrichment should be toeliminate the undesirable characteristics of highly

    repetitive, specialized work by enlarging it to include:Greater variety of knowledge and skill

    Giving a person a complete natural unit of work (module,division, area, etc.)

    More complex utilization of the important cognitive andmotor abilities possessed by the worker.

    More freedom and responsibility in the performance ofthe tasks at hand.

    Job Enlargement and

    Enrichment

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    Among the principles that commonly are applied in jobenrichment programs, the following are attended to byone large company.

    Ensure that there is variety in the job content.

    Include in the work situation an opportunity for the

    worker to grow and learn.

    Provide an opportunity for each worker to haveknowledge of the part that his or her job plays in the totalmanufacturing process required to produce the product.

    Design the work so that it has meaning to the worker andprovides pride in performance to the worker.

    Ensure that the work is reasonably demanding andfunctionally inclusive. Provide for self-direction of thework and for the checking of quality of output.

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    As a part of the approach to methods improvement, the

    methods engineer should question the impact of the design ofthe parts, the materials used, and the equipment used on theproductivity of operations.

    That is, the methods engineer should be thoroughly familiarwith value analysis, an activity that is closely both to themethods improvement programs and to purchasing and that isbeing used extensively in industry and the government.

    Value analysis is an objective study of every item of cost inevery component part, subassembly, or piece of equipment.

    This includes a study of the design, the material, and theprocess in a continual search for other possible materials and

    new processes. Value analysis involves the evaluation of anitems function and relates its effect to the end product.

    The purpose is to attempt to ensure that every element of costcontributes proportionately to the function of the item.

    Value Analysis

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    Modern industry is constantly searching for bettermethods. When a business ceases to move forward,it will lost ground and may eventually fail.

    It is for this reason that the major companies haveorganized industrial engineering groups, worksimplification and value analysis programs,suggestion systems, quality circles, and othermethods of achieving reduced costs of manufacturingtheir products.

    Social and Economic Effects of method Study

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    One of the consequences of these programs hasbeen increased mechanization, which, in turn, hasled to the production of more and more goods perwork hour.

    Among the long-range benefits derived from thisincreased output have been higher real wages, animproved standard of living, a shorter work week,and a reaction of the physical rigors of the job.

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    Thank You


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