Work Study.ppc.Class Lecture Butex

7/30/2019 Work Study.ppc.Class Lecture Butex

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WORK STUDY


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WHATISWORKSTUDY?

Work study is the investigation of the work done in an

organization by means of a consistent system, in order to

attain the best possible use of men, machines and

materials at present available conditions.In another way work study may be defined asThe

systematic, objective, critical and imaginative examination

of all factors governing the operational efficiency of any

specified activity in order to effect improvement.


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PURPOSEOFWORKSTUDY

In general work study aims to

Lower cost.

Increased productivity.

Increased profitability.

Increased job-security.

Make work easier.

Establish fair tasks for every one.

Check achievements against standards.


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Everyone in the industry gets benefit from work study

Management gets benefit through increased efficiency and thus

increased profit.

Worker is assured of a fair return for a fair days work. He is

protected unfair demands. The work is made easier and more

productive.

Trade union gets a reliable data measuring fair days work andpayment through work study. This enables trade unions to do

more objective negotiations with the management based on

factual evidence.

Productivity through work enables greater amount of

production and services to optimum quality and lower prices. Sothe consumers are benefit.


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MEANSOFINCREASINGPRODUCTIVITY

There are six possible lines of attack onproductivity problems, which can be classifiedas follows:

1. Improve basic processes by research anddevelopment.

2. Improve existing and provide better plant andequipment.

3. Simplify the product, reduce and standardizethe range.

4. Improve existing methods of plant operation.

5. Improve the planning of work and the use ofman-power.

6. Increase the effectiveness of all employees.

Long term requireCapital.

Intermediate may require

capital

Short term

wil l require li t t le

or no capi tal


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WORKSTUDYASFIELDOFAPPLICATION

The following diagram shows how work study helps in increasing

productivityWork Study

Work measurementMethod Study

To improve the methodsof production To assess humaneffectiveness

To achieve improved factory and workplace layout improved design ofequipment. Better working environment

reduction of fatigue resulting in improveduse of materials, plant equipmentmanpower.

To achieve a basis for comparison ofalternative methods correct initialmanning. Continuous economy of

manpower; effective planning ofproduction; realistic labour costing;basis for sound incentive scheme.

Higher Productivity


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METHODSTUDY

The aims of method study are-

Better design of plant equipments and buildings. Improved layout of factory and offices.

Better working conditions and environment.

Higher standards of safety and health.

Improved flow of work.

Better quality. Greater job satisfaction.

Higher earnings.

Improved utilization of resources.

Effective material handling.

Efficient process and procedure. Optimum inventory.

Optimum output.

Improved administration.

Waste reduction.

Standardization and rationalization.


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STEPSINVOLVEDINMETHODSTUDY

Select job/process to be examined & observe

current performance high process cost, bottlenecks, tortuous

route, low productivity, erratic quality

Record & document facts

activities performed

operators involved - how etc

equipment and tools used

materials processed or moved

apply critical examination - challenge job

components & necessity (purpose, place,sequence, method).

develop alternative methods & present

proposals

document as base for new work system

Install, monitor (slippage) & maintain


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METHODSTUDYACTIVITIES

There are the following 5 method activities as described below:-

1. Operation:An operation is an action performed for advancingtowards desired result.

2. Inspection:An inspection occurs when the product is

removed for a time from production.

3. Storage:A Storage occurs when the product is removed for atime from production.

4. Delay: A delay occurs when some undesirable eventprevents/hinders the next planned activity e.g. waitingfor a machine to be repaired. A traffic jam.

5. Transport:A transport occurs when there is movement fromone place to another.


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METHODSTUDYSYMBOLS

In order to make a vivid presentation of facts, and to enable themind to understand them quickly and clearly, we use somesymbols instead of words, for the method study activities.

Operation

Inspection

Storage

Delay

Transport


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RECORDINGTECHNIQUE

For recording data the following aids may be

utilized

Graphs.

Tables.

Schematic models.

Flow chart.

Templates.

Histogram.

Frequency polygons and ogives.


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The process recording methods are

1. Operation/Outline process chart.

2. Flow process chart.

3. Two handed process chart and left hand right hand

process chart.

4. Activity chart.

5. Multiple activity charts.

6. Flow diagram.

7. String diagram.

8. Templates.9. Models and Materials.

10.Cycle Graph and Chronocycle graph.


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CRITICALEXAMINATIONQUESTIONS

Purpose

What, Why, What else might & Should

be done ? Place

Where, Why, Where else & Whereshould it be done ?

Sequence

When, Why then, When else could &

When should ? Person

Who, Why, Who else might & shoulddo it?

Means

How, Why, How else could, How else

should

a sound reason for everyactivity

no assumptions so doublecheck

quality, safety and healthmust not compromised

The objectives of critical examination of recorded facts of an existing orproposed method is to determine the true reasons underlying each event

and to make a systematic list of all possible improvements for later

development in a new and improved method.


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WORKMEASUREMENT

Work measurement is the application of techniquesdesigned to establish the time for a qualified workerto carry out specified jobs at a defined level ofperformance.

We have seen how total time to manufacture aproduct is increased by:

adding undesirable features to product,

bad operation of the processes, and

ineffective time added because of worker and

management.

All this leads to decreased productivity.


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INTRODUCTION

Work measurement (WM) is concerned withinvestigating, reducing and eliminating ineffectivetime, whatever may be the cause.

WM is the means of measuring the time taken in theperformance of an operation or series of operations insuch a way that the ineffective time is shown up andcan be separated out.

In practice, proving existence of the ineffective time isthe most difficult task.

After existence is proved, nature and extent is easy tosee!

WM is also used to set standard times to carry out thework, so that any ineffective time is not includedlater.


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PURPOSEOF WM

To reveal the nature and extent of ineffective

time, from whatever cause,

So that action can be taken to eliminate it; and

then,

To set standards of performance that are

attainable only if all avoidable ineffective time is

eliminated and work is performed by the best

method available.


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USESOF WM

To compare the efficiency of alternative methods.Other conditions being equal, the method whichtakes the least time will be the best method.

To balance the work of members of teams, in

association with the multiple activity charts, sothat, as far as possible, each member has taskstaking an equal time.

To determine, in association with man andmachine multiple activity charts, the number of

machines an worker can run.


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TIMESTUDY

A WM technique for

1. Recording the times and rates of working for

the elements of a specified job carried out

under specified conditions,

2. Analyzing the data so as to obtain the time

necessary for carrying out the job at a defined

level of performance.


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STEPSINMAKINGATIMESTUDY

Obtaining and recording all the information

about the job, the operator and the surrounding

conditions, which is likely to affect the carrying

out of the work.

Recording a complete description of the method,

breaking down the operation into elements.

Examining the detailed breakdown to ensure

that the most effective method and motions are

being used.

Measuring and recording the time taken by the

operator to perform each element of the

operation.


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STEPSINMAKINGATIMESTUDY

At the same time assessing the effective speed ofthe working of the operative in relation to theobservers concept of the rate corresponding to

standard rating. Extending the observed times to basic times.

Determining the allowances to be made over andabove the basic time for operation.

Determining the standard time for theoperation.


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BREAKINGTHEJOBINTOELEMENTS

An element is an distinct part of a specified job

selected for convenience of observation,

measurement and analysis.

A work cycle is the sequence of elements which

are required to perform a job or yield a unit of

production. The sequence may sometimes include

occasional elements.

For each job, a detailed breakdown of the

complete job into elements is necessary.Because.


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REASONSFORBREAKDOWNOFJOB

To ensure that productive work (or effective time) isseparated from unproductive activity (or ineffectivetime).

To permit the rate of working to be assessed more

accurately than would be possible if the assessmentwere made over a complete cycle.

To enable different types of elements to be identifiedand distinguished, so that each may be accorded thetreatment appropriate.

To enable elements involving high fatigue to beisolated and to make the allocation of fatigueallowances more accurate.


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REASONSFORBREAKDOWNOFJOB

To facilitate checking the method and so thatsubsequent omission or insertion of elementsmay be detected quickly.

To enable a detailed work specification to beprepared.

The enable time values for frequently recurringelements, such as the operation of machinecontrol or loading and unloading work-pieces

from fixtures, to be extracted and used incompilation of the synthetic data.


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TYPESOFELEMENTS

Arepetitive element is an element which occursin every work cycle of the job.

An occasional element does not occur in eachwork cycle of the job, but which may occur at

regular or irregular intervals. e.g. machinesetting.

For a constant element, the basic time remainsconstant whenever it is performed. e.g. switch themachine on.

Avariable element is an element for which thebasic time varies in relation to somecharacteristics of the product, equipment orprocess, e.g. dimensions, weight, quality etc.


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TYPESOFELEMENTS

Amanual element is an element performed by a

worker.

Amachine element is automatically performed by

a power-driven machine (or process).

Agoverning element occupies a longer time than

any of the other elements which are being

performed concurrently. e.g. boil kettle of water,

while setting out teapot and cups.

Aforeign element is observed during a study

which, after analysis, is not found to be necessary

part of the job.


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RECORDINGTIMEFORACTIVITIES

Cumulative timing

The watch runs continuously throughout thestudy.

At the end of each element the watch reading is

recorded. The individual element times are obtained by

subsequent subtractions.

The purpose of this procedure is to ensure that

all the time during which the job is observed isrecorded in the study.

Typically, most work-study persons attain fairdegree of accuracy quickly when using thecumulative method.


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Fly back time

The hands of the stopwatch is returned to zero atthe end of each element and are allowed to startimmediately, the time for each element beingobtained directly.

In a comparative study of two methods carriedout the Purdue University, the average error inreading the watch using the cumulative method

was +0.000097 min per reading and using theflyback method was -0.00082 min per reading.


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Cumulative time recording is preferred, because:

Trainees achieve reasonable accuracy more quickly.

It does not matter if element times are occasionallymissed by observed; the over-all time of the study will

not be affected. Foreign elements and interruptions are automatically

included since the watch is never stopped.

Temptation to adjust the element time to rating isless compared to flyback time.

Workers have greater faith in the fairness as they seethat no time can have been omitted.

Flyback method can have slight delays when thestopwatch is snapped back to zero at the end of eachelement.


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TIMESTUDY: RATING

Rating is the assessment of the workers rate of

workingrelative to the observers concept of the

rate corresponding to the standard pace.

It is a comparison of rate of working observed by

the work-study person with a picture of some

standard level.

The standard level is the average rate at which

qualified workers will naturally work at a job,

when using the correct method and whenmotivated to apply themselves to their work.

This rate of working is called standard rating.


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TIMESTUDY: RATING

The purpose of rating is to determine from the

time actually taken by the operator being

observed the standard time which can be

maintained by the average qualified worker and

which can be used as a realistic basis forplanning, and incentive schemes.

Time study is concerned with speed at which

operator carries out the work, in relation to the

concept of normal speed. Speed here means the effective speed of

operation.


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FACTORSAFFECTINGRATEOFWORKING

Factors outside the control of workers include:

Variation in the quality or other characteristics

of the material used, although they be within the

prescribed tolerance limit.

Changes in the operating efficiency of tools or

equipment within their normal life.

Minor and unavoidable changes in methods or

conditions of operations.

Variation in the mental attention for the

performance of elements.

Changes in the climatic and other conditions.


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FACTORSAFFECTINGRATEOFWORKING

Factors within workers control:

Acceptable variation in the quality of theprocess/product.

Variation due to workers ability.

Variation due to ability of mind, specificallyattitude.

Optimum pace at which the worker will work

depends on The physical effort demanded by the work.

The care required on the part of the worker.

Training and experience.


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RATINGFACTOR

The figure 100 represents standard performance.

If the operator is apparently performing with less

effective speed, than the assigned factor is less

than 100.

If, on the other hand, the effective rate of

working is above standard, the operator gets a

factor above hundred.

Essential idea being:

Observed time x Rating = Constant


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RATINGFACTOR

This constant is known as the basic time:

So, depending on the rating assigned for the

operator, the basic time can either be less than or

greater than the observed time.

TimeBasicRatingStandard

RatingtimeObserved x


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WORKCONTENT

The work content of a job or operation is definedas: basic time+ relaxation allowance+ anyallowance for additional work (e.g. the part ofrelaxation allowance that is work related).

Standard time is the total time in which a jobshould be completed at standard performancei.e. work content, contingency allowance fordelay, unoccupied time and interferenceallowance.

Allowance for unoccupied time and interferencemay not be frequently included in the standardtime calculations; however, the relaxationallowance is.


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STANDARDTIMECONSTITUENTS

Acontingency allowance is a small allowance of timewhich may be included in a standard time to meetlegitimate and expected items of work or delays,precise measurement of which is uneconomicalbecause of their infrequent or irregular occurrence.

Contingency allowance for work should includefatigue allowance; whereas the allowance for delayshould be dependent on the workers.

Typically contingency allowances are very small andare generally expressed as percentage of the total

repetitive minutes of the job.

Contingency allowance should not be more than 5%,and should only be given where the contingenciescannot be eliminated and are justified.


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Relaxation allowance is an addition to the basictime intended to provide the worker with theopportunity to recover from the physiological andpsychological effects of carrying out specified

work under specified conditions and to allowattention to personal needs.

The amount of the allowance will depend on thenature of the job.

One of the major additions to the basic time.

Industrial fatigue allowance, in turn, forms amajor portion of the relaxation allowance.

Relaxation allowances are also given aspercentages of the basic times.


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Typical values of relaxation allowance are 12-

20%.

In addition to including relaxation allowances,

short rest pauses could be added over the period

of work for an operator.


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OTHERALLOWANCES

Start-up / shut-down allowance

Cleaning allowance

Tooling allowance

Set-up / change-over allowance Reject / excess production allowance

Learning / training allowance

Policy allowance is an increment, other than the

bonus increment, applied to standard time toprovide a satisfactory level of earning for certain

level of performances under exceptional

conditions.


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STANDARDTIME

Now, we can add all the constituents to arrive atthe standard time for a job.

Standard time = observed time + rating factor +relaxation allowance + work related contingency

allowance + delay related contingency allowance.

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Work Study.ppc.Class Lecture Butex