OUR-EnG Workstudy 1

8/9/2019 OUR-EnG Workstudy 1

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IE: Industrial Engineering Prepared by: Piyasena SamarakoonDept. of Mechanical Engineering, UOM

Page 1 Work-study & Job Design

Lesson 01: Workstudy & Job Design

Content

Aim and Objective

1.0 Introduction2.0 What is productivity?3.0 What is workstudy?4.0 What is method study?4.1 Human factors in enterprise operation

4.2 Method study procedure

4.2.1 Select the work to be studied

4.2.2 Record the existing work method and all other relevant facts

4.2.2.1 Recording Techniques and Tools

4.2.2.1 Recording Techniques and Tools

4.2.3 Examine the records

4.2.4 Develop the improved method

4.2.3.1 Classification of activities

4.2.3.2 Procedure of examination

4.2.4 Develop the improved method

4.2.5 Evaluate alternative method

4.2.6 Define the improved method

4.2.7 Install the improved method

4.2.8 Maintaining the new method

4.3 Methods and Movements at the work place

4.3.1 The principles of motion economy

.

Summary (Key Terms)

Reference

Aim and Objective

The main purpose of this lesson is to introduce scientific management approach to improve the productivity in a

production system. While, the importance of workstudy for the improvement of productivity is being emphasized, other

options available for the operations manager to improve productivity are brought into attention. The constituent elements

in workstudy are discussed in great details with their techniques and tools. Application of the tools and techniques are

discussed in manufacturing as well as service point of view, enabling to apply the concept for both goods and services.

Wherever possible, appropriate linked are placed with further reading and exploration.

In the core of this lesson, the following key questions are addressed:

What is Workstudy?

What is Productivity? Why is Workstudy important? What are the elements in workstudy? What are the techniques and tools used in work study? What is method study (MS)? What is work measurement (WM)? Where can MS and WM be applied?


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1.0 Introduction

Work study is an industrial Engineering Technique to improve productivity. It is very often used to increase the

production from a given quantity or resources without additional considerable capital investment (very small amount).

One of the most effective ways to raise productivity is often the development of new processes and the installation of

more modern plant and equipment. However, this is true only where production is dependent mainly on machines and

plant rather than on human labour. The research and development necessary to develop a new process or a machine of

higher performance are usually very expensive and lengthier process. In addition, there is always a risk that the

improvements achieved may not justify the amount time and money spent. In country like ours, where there is not much

capital to spend for improving the productivity, such approach may not be possible.

Workstudy has to be looked at keeping in mind the above mentioned factors. Work study concerns mainly with

operation rather than with technical processes. Therefore, it involves human beings: workers, planners, technicians,

managers, and so on. The study of processes and equipment leaving the operator behind is only a technical problem.

Workstudy is not usually concerned with it.

2.0 What is Productivity?

In common terms, productivity is the ratio of output to input, i.e. output/input. This definition applies in an enterprise, a

sector of economic activity, or economy as a whole. The term productivity can be used to assess or measure the

extent to which a certain output can be extracted from a given input. In case goods production, where both input and

output are tangible, productivity can easily be measured, but for intangible products, i.e. services, estimation of

productivity is difficult. For example:

Assume that a potter was able to increase the production of pots from 400 to 500 per month due to change in the

method of production but without changing other parameters such no. of hours worked per day (i.e. 8 hours per day).

His/her productivity calculated in terms of number of pots produced will then have increased by 25% (=100/400).

Let us now assume that as a result he was unable to sell pots and he had to lower his price from Rs. 20 to Rs. 18 a

pot. If the potter wants to assess the productivity gain, it may be more interested in using monetary terms rather than

simply number of pots produced. The potter can argue that the value of his output used to be Rs. 8,000 (400x20) a

month and is now Rs. 9,000 (500x18) a month. Hence the productivity gain is 12.5% [(9000-80000/8000].

From the above example, two observations are visible. First, productivity was used to measure increase in output

expressed in number of pots produced in the first case, and in monetary terms in the second, giving different values in

each case. In other words, depending on what one is interested in measuring, the nature of output and input will vary

accordingly. Second, while actual production increased in this example from 400 to 500 pots, productivity in monetary

terms did not show up the same corresponding increase. This means we have to distinguish between increased

production and increased productivity, which in this example was measured in terms of monetary gains. Now consider

the following examples:

Assume that the potter decided to replace the wood-fired kiln by and oil-fired kiln for the purpose of increasing the

productivity. This cost him an investment of Rs. 60,000, which he recons should be recovered in ten years time. In

other words, the cost of investment will be Rs. 6,000 (60,000/10) a year for ten years or Rs. 500 (6,000/12) a month.

He also would need oil that would cost him Rs. 500 a month more than what he would have paid for wood. Let us also

assume that the production also remained constant at 500 pots a month. Measured in monetary terms, the value of

his output is Rs, 9,000 per month as stated previously, from which will be deducted Rs. 500 for capital investment and

Rs. 500 for fuel, or total Rs. 1,000. Monetary value gain is Rs. 8,000 per month (9,0001,000). Thus the productivity

expressed in monetary gain has not improved since while keeping him in original value before the investment.

However, the potter wish to argue that as result of the new kiln, the quality of pots has improved and fewer rejects

were returned and the users satisfaction has increased over the time and as result the price may be able to increase.

From the potters viewpoint, it has become much easier to operate the new kiln.


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Here the definition of the output has been enlarged to encompass quality and reliability, intangible factor, that of

customer satisfaction. It also brought another factor satisfaction at work. Thus productivity gained gains become more

difficult to measure accurately because of these intangible factors and because of the time lag that needs to estimate

until users will permit an increase in price of the pots produced in the new kiln.

Therefore, productivity in the individual enterprise may be affected by a series of external factors such as availability of

raw materials and skilled labours, existing infrastructure, etc.; as well as by a number of deficiencies in its operations or

internal factors. External factors are beyond the control of the enterprise, but other factors are within the control ofoperations managers and these are outlined in next section.

3.0 What is Workstudy?

Workstudy, as the name implies, is the study of work performed by humans. Different authors have defined workstudy in

different view point and one of the general definitions is:

Workstudy is the systematic examination of the methods of carrying on activities numerous ways so as to improve the

effective use of resources and to set up standards of performance for the activities being carried out.

Workstudy then aims at examining the way an activity is being carried out, simplifying or modifying the method of

operation to reduce unnecessary or excess work, or the wasteful resources, and setting up a time standard for

performing that activity. The relation between productivity and the workstudy is thus obvious. If workstudy results in

cutting down the time of performing a certain activity by 20%, merely a result of rearranging the sequence or simplifying

the method of operation and without additional expenditure, then the productivity will go up be corresponding value,

which is by 20%. To appreciate how work study acts to cut down the costs and reduce the time of a certain activity, it is

necessary to examine more closely what that time consists of.

The time taken or a machine to carry out an operation or to produce a given quantity of a certain product may be

considered as made up in the manner illustrated in Fig. 1.1.

Fig. 1.1: Elements in Operation Time

Work Content: means the amount of work contained in a given product or a process measured in work-hoursor machine-hours.

Basic Work Content (A): is the time taken to manufacture the product or to perform the operation if the designor specification of the product or service provided were perfect, if the process or method of operation were

perfectly carried out, and if there were no loss of working time due to any reason, other than legitimate rest

permitted to the operatives. Basic Work Content Time is the minimum time theoretically required to produce one

unit of output. This is obviously a perfect condition which never occurs in practice. In general, actual operation

times are far in excess of it on account of. The work content is increased by the other reason stated in the figure.


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B.1 Product

development

B.2 Proper material

utilization

B.3 Quality control

C.1 Layout andprocess planning

C.2 Production

planning

C.4 Workstudy

(method study)

C.2 Material handling

C.5 Inventory control

C.6 Preventive

maintenance

(A)

Basic Work Content

Work content added

by poor product

Design/material

utilization

Work content added

by inefficient

methods of

manufacture/

operation

Basic Work

Content of product

and/or operation

D.1 Proper

management &

policy

D.2 Training

D.3 Improved working

condition

Work contentresulting from the

contribution from

human resources

Total work

content

Total time,

if all perfect

Ineffective time

totally eliminated,

if all perfectly

applied

(A)

Basic Work Content

B.1 Poor design and

frequent design

changes

B.2 Waste of material

B.3 Incorrect quality

standard

C.1 Poor layout andutilization space

C.2 Frequent stoppage

as production

changes from one

product to another

C.4 Ineffective method

of work

C.2 Inadequate

material handling

C.5 Poor planning of

inventory

C.6 Frequent

breakdown of

machines and

equipment

D.1 Absenteeism and

lateness

D.2 Poor workmanship

D.3 Accidents and

occupational

hazards

Fig. 1.2: Work Content and Management Technique


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Work Contents Added by Poor Design or Material Utilization (B): There are several ways in whichunnecessary time and waste can be contributed to poor design of product or its parts, or to incorrect quality

control.

o Poor design and frequent design changes (B.1): The product may be designed in such a way that itmay require a large number of non-standard parts causing a lengthy time of assembly. Excessive

variety of products and lack of standardization of products or their parts may mean that work has to be

produced in small batches, with time lot as the operator adjust and shifts from one batch to the next.

o Waste of Material (B.2): Over design cause excessive material removal time and waste of material.Operations requiring cutting in particular need careful examination to see of the resulting waste can be

reduced to minimum or reused.

o Incorrect Quality Standard (B.3): Low or high quality can increase work content. In Engineering, highaccuracy cause extra machining and high machining time. Low accuracy too may result in a large

number of rejects. Therefore, deciding appropriate quality standard and method of quality control is an

important consideration.

Work Contents Added by Inefficient Methods of Manufacture or Operation (C): Ineffective time and highercost can be caused due to poor method of carrying out the operation, resulting in unnecessary movements of

persons and materials, and many other reasons. Fig. 1.3 shows the potential reasons for added work contentsand management that can reduce the work content time.

o Poor layout and utilization of space (C.1): The space used for operation represents an investmentand higher utilization of space results high cost of production and services. Poor layout increases the

movement and movement time and effort.

o Inadequate material handling (C.2): Use of proper and efficient material handling equipment can savetime and effort.

o Frequent stoppage as production changes (C.3): Frequent change of orders creates more setting uptime for operators and machines. Proper planning and control of production operations can ensure that

one batch or order follows immediately on another, eliminating time for machinery and equipment.

o Ineffective method of work (C.4): A sequence of operations may be well planned but each or some ofthem may have done in unplanned manner. By examining the way a certain operation is carried out and

devising a better method, ineffective time can be reduced. This is called Workstudy.

o Poor Planning of Inventory (C.5): Input, output and work-in-progress inventory tied up investment,but reduction of inventory in input & work-in-progress stages increases the time for production. A proper

inventory control system minimizes such an idle investment and ensures the material for next stages.

o Frequent Breakdown (C.6): Poor maintenance causes frequent break downs and thus interruption toproduction and delays. Preventive maintenance system ensures smooth functioning of the system.

Work Contents resulting from the Contribution from Human Resources: Workers in an enterprise caninfluence the time of operations voluntarily or involuntarily.

o Absenteeism and Lateness (D.1): Non availability of safe and satisfying working environment causeabsenteeism, lateness and ignorance.

o Poor Workmanship (D.2): Poor workmanship results re-work causing wasted material and time.o Accidents and Occupational Hazards (D.3): Failing to provide safe, healthy environment causes

occupational illness, lack of moral and subsequent time increase.

If ineffective work content is reduced; the cost of production can be reduced and/or maximum productivity could be

achieved. Therefore, workstudy specialists should keep all above options on focus in their workstudy exercise.


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Work Study

Method Study

(to improve method

of production)

Work Measurement

(to assess human

effectiveness)

Resulting in more

effective use of

material, plant & equipment

and manpower

Making possible improved

planning and control and

as a basis for sound

Incentive scheme

Higher productivity

Work Study

Method Study

(to improve method

of production)

Work Measurement

(to assess human

effectiveness)

Resulting in more

effective use of

material, plant & equipment

and manpower

Making possible improved

planning and control and

as a basis for sound

Incentive scheme

Higher productivity

The above description depicts that ineffective time can be reduced by examining the way a certain operation is carried out

and devising a better method. In this respect, the definition provided in British Standard 3138: 1969 gives the insight intoworkstudy activities.

A management service based on those techniques particularly Method Study and Work Measurement, which are

used in the examination of human work in all its context, and which leads to the systematic investigation, if all the

resources and factors which affects the efficiency and economy of the situation being reviewed, in order to effect

improvement.

Similar definition presented by International labour office, ILO, Geneva, 1960 also highlights the issues of workstudy

techniques:

Work study is a term used to embrace techniques ofMethod Study and Work Measurement which are employed to

ensure the best possible use of human and material resources in carrying out special activity.

Therefore, workstudy constitute two groups of techniques which are distinct from each other but completely

interdependent. These groups have been subtitled Method Study and Work Measurement as shown in Fig. 1.3. As the

diagram shows, one technique is concerned with the way work is done (the method) and the other is concerned with

value or work content of the task itself.

Fig. 1.3: Workstudy Techniques

Method Study: the systematic recording & critical examination of existing and proposed ways of doing work asa means of developing and applying easier and more effective methods, and reducing costs.

Work Measurement: The application of techniques designed to establish the time for a qualified worker tocarry out a specified job at a specified level of performance.

Method study and work measurement are, therefore, closely linked. Method study is concerned with reduction of the

work content of a job or operation, while work measurement is mostly concerned with the investigation of any ineffective

time associated with it; and with the subsequent establishment of time standards for the operation when carried out inthe improved fashion, as determined by method study.

The aim of workstudy is to assist management to obtain the optimum use of human and material resources available to

an organization. Fundamentals this aim has three folds:

the most effective use of plant of equipment, the most effective use of human effort, and the evaluation of human work.


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The above description collectively establishes the objectives of the workstudy:

to analysis, design and improve of work systems, work places and work methods; to establish work standards for determining requirements in manpower and equipment, assessing

performance, planning operations, costing operations, products and services, and paying workers;

to develop an application of job evaluation schemes based on job descriptions; to specify work facilities, layout, space utilisation and material and ` traffic flows; to evaluate and optimize alternative combinations of personnel, material and equipment; to develop procedures for the planning and control of work and material usage; and to develop procedures for presenting information to management about work performance.

4.0 What is Method Study?

As stated previously, Method Study is the systematic recording & critical examination of existing and proposed ways of

doing work as a means of developing and applying easier and more effective methods, and reducing costs.

Accordingly, the purpose of method study is to find better ways of doing things in order to improve efficiency by getting

rid of unnecessary work, avoidable delays, and other form of waste. This purpose or objective is achieved through the

following:

improved design and layout of factory or work place, improved working procedures, improved use of man machine and material, improved working environment, and improved design or specifications of the end product.

As the method study aims to establish a method for a job or to review and improve existing methods, the types of

problems which are likely to be concerned are:

Getting a job done more efficiently and so more cheaply;

Rationalising the work - questioning whether work needs to be done at all, or whether it can at least be donemore simply and with less effort; alternatively, trying to establish whether better use can be made of existing

idle time by spreading employees work loads more evenly over their working time.

A method study may be part of routine auditing of the organisation affairs, or it may be requested by departmental or

senior management. It may arise from:

The introduction of new products, services or equipment; The identification of problems:

o Bottlenecks, causing unbalanced workflowo

Idle workers or equipment i.e. under use of resourceso Poor morale indicated by trivial complaints or absenteeismo Escalating costso Excessive errors due to rejected worko Inconsistent earnings, where the earning of employees are not related to output

Method study provides a comprehensive routine for improving methods of work. Frank Gilbreth (1886 to 1924) made a

major contribution to the techniques of method study, by presenting a detailed and objective approach.


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4.1 Human Factor in Enterprise Operation

Before dealing with method study procedure or the exercise, some other factors, in particular human intervention, have

to taken into account while considering the study should be carried out or not.

The human factor is one of the most crucial elements in enterprise operation, for it is through people that management

can control the utilization of its resources and the sale of its products and services.

Workstudy and Supervisor: The work study specialists most difficult problem may often be the attitude of supervisors.

They must be won over if he or she is to obtain good results from the work study exercise. If it is evident that supervisor

thinks that this workstudy stuff is nonsense, the workers will not respect the specialist and will make no efforts to carry

out his or her suggestions, which, in any case, have to come to them through their supervisor.

Before the workstudy starts, the whole purpose and the procedure of the workstudy should be explained to supervisor so

that he or she could understand exactly what is being done and why. Unless, the supervisor is likely to be difficult, if not

actually obstructive, for many reasons such as:

If any improvement takes place through the exercise, they feel that their prestige in the eyes of their superiorsand of the workers will be lessened.

In some firms, planning & development work, hiring and firing workers, etch are done by the supervisors. Themere fact due to exercise that some of their responsibilities are taken away is likely to make them or theirexperience a loss of status.

Supervisors are the first people who will called upon to clear matters up, and is difficult for them to do so fairly ifthey do not understand the situation.

In some countries, the supervisors are selected on the basis of seniority from among the best-skilled persons inthe enterprise and they are often in middle-age and there is tendency to select method on their own ways. They

also find it difficult to believe that they have anything learn from someone who has not spent a very long time in

the same occupation.

To avoid the above situation, the supervisors should trained on workstudy techniques and during the exercise, the

supervisors should be consulted in approaching the workers on changing the work pattern, giving opinions, etc..

Workstudy and the Worker: This is the most important and unpredictable factor. Workstudy exercise may result the

workers positively as well as negatively.

One of the greatest difficulties in obtaining active cooperation of workers is the fear that raising productivity through the

workstudy exercise will lead to unemployment. Workers are afraid that they will work themselves out of their jobs. This

anxiety is greatest when unemployment is high and worker who looses his or her job will find it hard to find another. Even

in industrialized countries, where the level of unemployment is relatively lower than developing countries, this fear is very

real to those who have experienced unemployment.

Any changes to working method or the methods proposed by study may cause mental and emotional reactions from

workers as it will change their familiar method. Knowledge of local personnel and local condition should reduce such

difficulties. Experience has shown that if the study of a particular job creates unrest or ill-feeling among worker, it is

better to leave it alone. The following action can be proposed for dealing with workers in the workstudy exercise:

Do not emphasize the productivity enhancement through labour. Do not hide from or act against for the worker and be frank with the worker. Inform fully the purpose of workstudy to workers representative. Ask suggestions and get involve with the worker for development of working place. Get involve with selected workers for the exercise through educating workstudy techniques. Highlight the purpose is not only productivity improvement, but also work place improvement.


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On the other hand, workers sometimes feel positively about the workstudy mainly because they consider such a study is

sort of recognition for them.

Workers feel that the management cares for them Workers discover that there are managers who highly understand their job Improving the feeling of confidence

Workers are more able to carry out their jobsWorkstudy and Management: Applying workstudy in one working area can start a chain reaction of investigation and

improvement which will spread in all directions throughout the organization: to the engineering department, the account

department, design office, sales department, etc. If the application of workstudy in an enterprise is to succeed, it must

have the understanding and the backing of management at all levels. Therefore, at the beginning, it is essential all

parties in the management to aware the purpose of the workstudy and likely outcome alone with potential effect on each

division.

Workstudy and Practitioner: Any one who is going to undertake improvements in methods should have an inventive

turn in mind, be capable of devising simple mechanisms and devices which can often save a great deal of time and

effort, and be able to gain the cooperation A from most of the parties involve with the exercise. Personal qualities in this

respaect play an important role in addition to the knowledge and experience of the practitioner and the following qualitiesmay be found such a practitioner.

Sincerity and honesty: able to gain the confidence and respect from all involved. Enthusiasm: believe in the importance of what he or she is doing and able to transmit enthusiasm to people

around.

Interest in and Sympathy with People: get along with people at all levels and be able to see views of differentpeople and their motives.

Tactful: dealing with different types of people and understand the feeling as well as toughness situation. Good Appearance: neat, tidy and look efficient to inspire among the people. Self Confidence: able to stand up to top management to workers and defence of his/her opinion and findings.

4.2 Method Study Procedure

Method study procedure consists of six main steps to complete the exercise as in Fig. 1.4. These steps constitute the

logical procedure that a workstudy specialist could normally apply. In practice, however, the procedure is not straight

forward. For example, when measuring the results achieved by the new method, one may find that the resulting cost-

effectiveness may be negligible and does not warrant the added investment in time and effort to develop the perceived

method. In such case, job will have to be examined and another method should be developed. In some other instances,

the new method may bring a new issue to the surface, in which case the last few steps should be repeated.

4.2.1 Select the work to be studied:

Jobs which are likely to produce significant savings as a result of study have to be selected first. When selecting a job for

method study it is better to have a checklist indicating the points to be covered. A sample of a checklist that could be

adapted for individual needs is presented below.

Product and operation

Person who proposes investigation

Reason for proposal

Suggested limits of investigation

Particulars of job


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o quantity produced or handled;o percentage of above quantity handled in the department selected;o number of workers (direct and indirect);o duration of the job;o whether the above duration increase in future;o grade of workers and their pay;o average output per worker (or team) per day;o output per day compare to output per hour;o method of payment, i.e. price-rate or time-rate;o daily output of a best and worst worker;o date of production standard set;o whether the job is unpleasant;o equipment cost and utilization;o layout whether spaces is enough for the jobo etc..

Product details

o Whether there are frequent changes;o Whether the product design could be simplified;o What quality is needed;o Type of quality control;o etc..

Expected savings or productivity involvement after a method study

Etc.

In the selection process, due consideration must also be given to:

Economic feasibility: asking question Will it worth to begin a method study of this job? Will it pay to continuethis study? Obvious choices for the study are:

o Key profit-generation or costly operations, or ones with the largest scrap/waste rates.o Bottleneck that are holding up other operations, or lengthy operations that consume a great deal of time.o Operations involving repetitive work using a great deal of labour & ones that are likely to run for long time.o Movements of material over long distance between work stations, those involving the use of relatively

large proportion of labour or which require repeated handling of material.

o Jobs that are involved with excessive over timePareto Analysis: One of the easiest techniques that used to identify key operations is the Pareto Analysis (or ABCanalysis). For example, assume that an enterprise produces 20 different products and each of products generate a

certain profit as given in Fig. 1.5. Total profit column has been created considering the annual production and unit profit.

According to the figure, three items accounts for 60% profit, which are the most profitable products. Therefore, they

would be a priority of study. Seven products contribute 25% of the profit and they are assumed as second importance.

Other products give lower profit and thus study may not take place for them.


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Product

No.

Annual

Production

Profit per

Unit (Rs.)

Total Profit

(Rs.)

Pareto or ABC

Analysis

17 1,200 50 60,000

60% of the profit4 800 40 32,000

9 1,400 20 28,000

14 1,600 8 12,800

25% of the profit

11 1,800 6 10,800

12 2,000 3 6,000

19 1,200 5 6,0002 1,200 4 4,800

3 1,600 3 4,800

15 1,600 3 4,800

1 7,000 0.6 4,200

15% of the profit

16 5,000 0.8 4,000

18 8,000 0.5 4,000

6 7,200 0.5 3,600

10 4,000 0.9 3,600

13 6,000 0.6 2,400

8 2,400 1 2,000

20 5,000 0.4 1,600

5 3,200 0.05 1,6007 4,000 0.25 1,000

Fig. 1.5: Pareto Analysis: Profit Contribution Fig. 1.4: Method Study Procedure

The similar type of analysis can be conducted to determine , for example, the most costly product or process or the

products or processes that yield the highest waste, depending on the requirement. Fig. 1.6 shows the use of Pareto

Chart for the analysis of the importance of activity or most time required for operation (i.e. bottleneck of operation).

Fig. 1.6: Pareto Chart

Technical feasibility: One of the important consideration is the desire by management to acquire moreadvanced technology, whether in equipment or in processes. Thus management may want to computerize its

office paperwork or its inventory system, or to introduce automation in the production operations. Before such

steps are taken, a method study can point out the most important needs of the enterprise in this respect. Thus

this is to make sure that adequate technical knowledge is available with which to carry out the method study.

Another example is that a machine tool has become a bottleneck in production. The machine is known to be

running at a speed below that of high-speed-steel tool. Can it be speeded up? Can the machine is robust

enough to take the faster speed? This problem is for the machine-tool expert.


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Human Factors: This is important, but unpredictable factor. Some operations cause dissatisfaction to workers.The level of satisfaction points out a need for workstudy. In such a case, selection of job for the study is much

easier. Some study may lead to unrest or ill-feeling. Sometimes, the study or implementation should be

abandoned even if some significant benefits are obvious.

Limiting the Scope: The first decision in the selection process is to define the type of work to be studied, to set up

boundaries around it and to decide what exactly the study encompasses. For example, it is essential to decide the scope

of the investigation with respect to each product or process in the example considered in Pareto analysis.

To assist in making such decisions, it is important to understand thoroughly the problem in hand or the present situation

before looking for solutions or improvements for which others perception may be useful. The rule of thumb is that the

scope of the study should be decided at the very beginning before starting any other activity.

4.2.2 Record the existing work method and all other relevant facts:

Having selected the work to be studied, all the facts relating to existing method should be recorded. The success of the

whole procedure depends on the accuracy with which the facts are recorded, because they will provide the basis of both

critical examination and the development of improved method. Recording serves essentially as a basis for subsequent

analysis and examination. Recording may be carried out in two phases: first, rough sketch or charting of the job being

studied to establish whether the recorded information is of use; and second, a more formal and accurate charts or

diagrams to include clear and precise details.

The usual way of recording facts is to write them down. But, such method is not appropriate for complicated processes.

This is particularly is true when an exact record is required every minute details. Needless to state that in order to

describe everything that is done in even a very simple job, which takes perhaps a few minutes to perform, would

probably result in several pages of closely written script overcome this difficulty, other techniques and tools of recording

have been developed, so that detailed information may be recorded precisely in standard form.

4.2.2.1 Recording Techniques and Tools:

The most common techniques are charts and diagrams. There are several types of standard charts and diagrams

available, each with its own special purpose. In broad sense, they fall into two groups:

oThose which are used to record process sequence, i.e. series of events or happening in the order in which theyoccur, and

o Those which record events, also in sequence, but on a time scale that enables to interact with related events.The diagrams are used to indicate movements and/or interrelationships of movements more clearly than charts. But,

they do not show all details recorded on charts, which they supplement rather than replace. The most commonly used

method study charts are given in Fig. 1.7.

Process Chart Symbols: The recording of the facts about a job or operation of a process chart is made much easier by

the use of five standard symbols, which together serve to represent all the different types of activity or even likely to

encountered in any factory or office. Name, Symbol and the description of each standard symbol are shown in Fig. 1.8.

Fig. 1.7: Common Charts and Diagrams

Type Base Name

Chart Indicate process

sequence

Outline process chart

Flow process chart workflow type, material type,

equipment type

Two handed process chart, Procedure flowchart

Chart Use time-scale Multiple activity chart

Simo chart

Diagram Indicate

movement

Flow diagram, String diagram, cycle graph,

Chronocyclegraph, Travel chart


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Symbol Name Description

OPERATIONIndicates the main steps in a process, method or procedure.

Usually the part, material or product concerned is modified

or changed during the operation.

INSPECTION Indicates an inspection for quality and/or check for quantity

TRANSPORTIndicates the movement of workers, material or equipment

from place to place

DELAY or

TEMPORARY STORAGE

Indicates a delay in the sequence of events: e.g. waiting

between consecutive operations

PERMANENT STORAGEIndicates a controlled storage in which material is received

into or issued from s store

DECESION Indicates the decesion point for other operation

Fig. 1.8: Process Chart Symbols

Different Symbols Used in Different Process Charts: Not all symbols are used in each process chart (in outline, flow

& two-handed process chart). Fig. 1.9 compares the different symbols used in different process charts.

Fig. 1.9: Symbols Used in Different Process Charts

Outline Process Chart: It is often valuable to obtain a birds eye view of a whole process or activity before embarking

on a detailed study. This can be obtained by using an outline process chart. Therefore, it gives overall picture by

recording in sequence only the main operations and inspections. In addition to the information given by the symbol

and their sequence, a brief note of the nature of each operation or inspection is made besides the symbol, and the time

allowed for it is also added. Fig. 1.10 shows an example for outline process chart.

Flow Process Charts: Once the general picture of a process has been established through outline process chart, it is

possible to go into greater detail. The first stage is to construct a flow process chart.

Therefore, flow process chart can be defined as a chart setting out the sequence of the flow of a product or a procedure

by recording all events under review using appropriate process chart symbols. However, flow process charts are used

for different operations to show: what the operator does, how the material is handled or treated and how the equipment

is used, i.e. worker-type, material-type and equipment type. It is prepared in the manner similar to that in which the

outline process chart is made, but using, in addition to the symbols for operation and inspection, those for transport,

delay and storage.


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Fig. 1.10: Example for Outline Process Chart

It is usual only one printed form of chart for all three types, the heading bearing the word Worker/Material/Equipment.

When flow process charts are being used regularly, it is convenient to use printed sheets similar to Fig. 1.11, which

illustrates a several process to be carried on a bus engine for maintenance purpose.

Fig. 1.12 shows flow diagram and process chart for clerical operation in an office environment.

Fig. 1.13 shows flow process charts of two types (worker and material) shown in one sheet for writing a letter by short-

hand typist.


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Fig. 1.11: Common Sheet for Flow Process Chart


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Fig. 1.12: Flow Process Chart for Clerical Operation


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Fig. 1.13 Flow Process Chart for Writing a Letter by a Short-Hand Typist

BEFORE PRESENTING WITH OTHER RECORDING TECHNIQUES, EXAMINE AND DEVELOP STEPS ARE NOW

DISCUSSED SO THAT THEIR MERITS AND DEMERITS COULD BE DIFFERENTIATED EASILY.

4.2.3 Examine the Records

Once the recording of a job is over, the next step is to examining the records critically. During the examination, it may

find that some essential details have not been recorded. In such cases, it is necessary either to improve the records or to

choose a different or a better recording procedure. Therefore, critical examination is considered the most important part

of the basic procedural steps in method study.


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Within the examination process, transportation and delay may generally appear to give greatest scope for

improvement. It may even be possible to eliminate certain operations, which will automatically affect transportation and

delays. Therefore, an examination of the operations in a process should first be made.

4.2.3.1 Classification of Activities

Five sets of activities recorded in flow process charts by the five symbols namely operation, transport, inspection, delay

and storage fall naturally into two following main categorize:

1. Activities in which something is actually happening to material or work piece under consideration, i.e. it is being

worked upon, moved or examined

2. Activities in which it is not being touched, being either in storage or at a standstill owing to delay

The first category is the productive activities and they can be further divided into three groups

Make-Ready Activities: These activities are required to prepare the material or work piece and set it in positionready to be worked on. Activities such as loading, transporting, etc. are fall into this category.

Do Activities: These activities occur when the material of the product is changed either in shape, compositionor condition. Activities such as stitching the collar to shirt, typing the letter on to the paper are such activities.

Therefore, Operation is the key element in this category and a significant value is added to the process.

Put-Away Activities: These activities occur when the material or work piece is moved aside from the machineor work place. Put-Away activities in one operation may be the Make-Ready activities for the next operation.

For example, transporting material or work-in-progress items from one working station A to next station is Put-

Away activity for station A, but Make-Ready activity for station B. Putting parts into storage and inspecting

finished parts are other examples for Put-Away activities.

It is clear from above classification that it will be beneficial to have high proportions of Do activities which carry the

material towards completion. In service sectors, Do activities are those operations which actually carry out activity for

which organization exists, for example the act of selling in a shop or act of typing in an office. It is only during these

activities, the value is added to the process or product.

Therefore, Do activities are productive activities and all others, though necessary, may be considered as non-

productive activities, including storages and delays which represent tied-up capital that could have been used to further

the business. Such activities do not add value to the product or process.

On of the main focus on the productivity improvement process is to eliminate non-value added activities. Do activities,

i.e. value added activities could be sometimes either eliminated or modified resulting in elimination of the connected

Make-Ready and Put-Away as well as corresponding transport and delays.

4.2.3.2 Procedure of Examination

Critical examination is carried out by asking two sets of systematic, detailed and progressive questions. At this point, it is

worth to state that there is old way of saying that to ask the correct questions, the correct answer is to be half-way

towards the finding the correct answer. This is especially true for method study. The two sets of questions are:

1. Primary questions, and

2. Secondary questions

Primary Questions: These are to establish the facts and reasons underlying the study. In this process, the purpose,

place, sequence, person and means of each activity recorded are systematically queried, and reason for each reply is

sought. The following are the primary questions to be raised with a view of eliminating, combining, re-arranging or

simplifying the activities (Refer Fig. 1.14).


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Purpose:What is actually achieved?

Why is the activity necessary at all?

Place:Where is it being done?

Why is it done at that particular place?

Sequence:When is it done?

Why is it dome at that particular time?

Person: Who does it?Why is it dome by that particular person?

Means:How is it done?

Why is it done at that particular way?

Fig. 1.14: Primary Questions in Examine Process

The first question what is actually achieved ensures that whatever is written as description against the symbol on a

chart is accurately stated and properly understood. In this way, the real achievement of the activity is established. The

purpose of the primary questions is to ensure that every fact on an existing method is clearly understood. It is therefore

important not to confuse the questions and answers relating to purpose and means. For example, when considering the

operations of tying a parcel with string, the question under purpose, what is actually achieved?, would receive the

answer, the parcel is fastened, but not the parcel is tied up with a string.

Secondary Questions: These are primarily to search for alternatives, which might lead to improvement. These

questions cover the second stage of the questioning technique, during which the answers to the primary questions are

subjected to further query to determine whether possible alternatives of purpose, place, sequence, person, and means

are practicable and preferable as a means of improvement upon the existing method.

Therefore, during this stage of questioning (having asked already about the activity recorded, what is done? and why is it

done?), the method study specialist goes on to inquire: What else might be done? And hence: What should be done?

In the same way, the answers already obtained on place, sequence, person and means are subjected to further query. It

is clear that in this stage, two sets of questions are to be asked to set out the alternatives. The Fig. 1.15 lists out such

questions to be asked for each category.

Purpose: What else could be done? What should be done?

Place: Where else could it be? Where should it be done?

Sequence: When else could it be? When should it be done?

Person: Who else could it be? Who should do it?

Means: How else could it be? How should it be done?

Fig. 1.15: Secondary Questions in Examine Process

The last set of questions would indicate the direction along which a new method should be developed. However, it is not

possible at this stage to make adequate decisions to develop the new method. In obtaining the answers to the secondary

questions, the following considerations are of primary significant;

1. When an activity is challenged, the purpose is to see whether it can be eliminated entirely

2. If the activity can not be eliminated because it is essential, then it is required to see how it could be best done

3. Attention must also be given to see the activity can be combined with any other activities

The above queries are to be made systematically every time a method study is undertaken. Such an approach is the

basis of successful method study.


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4.2.4 Develop the Improved Method (Step 4/5)

Through the critical examination, one can develop a fairly good notion about the shortcomings of the present operation

and the possibilities of a new improved method begin to immerge. In many cases, however, the solution is not all that

obvious and further investigation may be needed elsewhere. It is therefore unwise to rush into solutions before

investigating these other related areas such as material handling, inventory control, layout design, etc. It is therefore,

workstudy person should be aware of the ranges of techniques that are available to them in developing a new method.

Once the step of developing a new method is accomplished, it is recorded on a corresponding chart. For such, thiswould be a flow process chart so that it can be compared with the original method and checked to make sure that no

point has been overlooked.

The development and improvement of the work method may not be obvious in most of the cases. A thorough,

exhaustive and time consuming examination is normally required. The device specifically designed for improving work

method is known as process improvement formula. The formula consists of four steps and they are:

1. Eliminate

2. Combine

3. Sequence

4. Simplify

The above steps are applied to each separate activity in the job, i.e. each meaningful group of elements. Completeelimination of unnecessary activities is clearly the most important step that can be taken in developing an improved work

method. An activity may have been retained because of custom, history, inertia, inadequate communication or even

ignorance. Changes to materials, product design, process design, tools or the work place may facilitate basis for

elimination or combination.

If none of the eliminating or combining attempt succeeded, then more expensive step should be considered, i.e. attempt

to simplify the activity by reducing the number of operations, reducing or eliminating delays & storages or minimizing

transportation. It may become necessary to conduct a more detailed study to obtain sufficient information to enable

activities to be simplified.

The purpose of simplifying the activity is to permit the worker to complete the job more quickly and easily. Gilberts work

on principle of motion economy is valuable in devising the best method of doing a manual task. In his study of motion

economy, Gilbeth considers aspects such as use of workers body, arrangement of work place and design of tools and

equipment. A list of rules related to the eliminating and combining aspects were given by Gilbeth and other later workers

on motion economy with greatly helps developing work methods.

OTHER RECORDING TECHNIQUES and EXAMPLES FOR EXAMINE & DEVELOP

Example for Examine Record: The process chart given Fig. 1.11 regarding engine maintenance shows the activities

associated with the process. Examination of the chart shows that a very high proportion of non-productive activities.

There are in fact four operations and one inspection, while there are 21 transports and three delays. Out of all 29

activities, excluding the original storage, only five can be considered as productive.

Detailed examination of the chart leads to a number questions. For example, it can be seen that an engine being

transported from the old-engine stores has to change cranes in the middle of its journey. This shows the necessity of

examining the activity critically and the following primary & secondary questions (Fig. 1.16) can be seen as appropriate.

In the event this suggestion was adopted, and as result three transports can be eliminated. Moreover some operation

or sequences of operations are performed without valid reasons and they could be eliminated or combined. After

examining the records critically, with adopting the suggestions, the flow diagram of the process could be proposed as

given in Fig. 1.17 and the process chart for the improved process is shown in Fig. 1.18.


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What is done? The engine is carried to the stripping bay

How is this being done?By an electric crane, The engine is placed on the ground and

pickup by another crane to be transported to stripping bay

Why is this done?Because the engine can not be directly be picked by the monorail

crane that runs through stores and the shop.

What else might be

done?

The engine should be stored so that they are immediately

accessible to the monorail crane.What should be done? The above suggestions should be adopted

Fig. 1.16: Example for Questions

Fig. 1.17: Existing and Improved Flow Diagram


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Fig. 1.18: Process chart for Improved Process

The questioning process could be performed very rapidly by experience specialist. In fact, it uses more common sense

while observing the activity with the focus of answering What is done? and Why is it necessary?


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Use of Flow Diagram with a Flow Process Chart: Fig. 1.19 shows the original layout of the receiving department of

an aircraft factory where inspection and making off incoming parts takes place. Symbols of various activities have been

inserted into the flow diagram into it-self for recording purpose. The Fig. 1.20 gives different activities associated with

existing inspection and marking process of incoming parts. With critical examination of the records, the layout diagram

has been improved to reduce the total time for the entire process. The combined flow diagram and the process chart for

the department and the flow process chart for the inspection and marking processes are shown in Fig. 1.21 and Fig. 1.22

respectively.

Fig. 1.19: Flow Diagram: Inspecting & Marking Incoming Parts (Existing Method)


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Fig. 1.20: Flow Process Chart: Inspecting & Marking Incoming Parts (Existing Method)


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Fig. 1.21: Flow Diagram: Inspecting & Marking Incoming Parts (Proposed Method)


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Fig. 1.22: Flow Process Chart: Inspecting & Marking Incoming Parts (Proposed Method)


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Flow Diagram:As experienced in previous examples, flow diagram drawn substantially to scale and which shows the

location of specific activities carried out and the routes followed by workers, material or equipment. Flow diagrams are

very popular and useful as it is very convenient to understand.

String Diagram: There are many types of activities in which workers move at irregular intervals between a number of

points in the working area, with or without material. This situation is very common in industry and commerce and even in

the home. A few examples of such are:

An operator is looking after more than one machine Labourers are delivering materials to or removing work from a series of machines or workplaces In stores and shops where a variety of materials are being removed from or put away into racks and bins In restaurant and canteen, staff move to different location during the preparation of meals

One of the simplest, but most useful techniques for recording this form activities are string diagram. It is a scale layout on

which a length of string is used to record the extent as well as the patterns of movement of a worker or material working

within a limited area during a certain period of time (e.g. a few hours) until gets the true picture. Although, it can be used

in places where the movement is a simple backward and forward one between two or three fixed points, it is most value

where the journeys are so irregular in distance and frequency that it would otherwise be difficult to see exactly what is

happening.

Fig. 1.23: String Diagram for Tile Flow

The string diagram shown in Fig. 1.23 is thus a special form of flow diagram, in which a string is used to measure the

distance travelled in ware house operation of tiles. Because of this, it is necessary that string diagram be drawn to scale

unlike ordinary flow diagram. The string diagram is started in exactly the same way as all other method. Both flow

diagram and string diagram are often used to supplement flow process chart enabling to provide a clearer picture. If the

journey is long and study area is fairly large, methodical notes such as the direction of flow, arrival t& departure times

should be noted clearly to avoid later confusion.


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The string diagram in Fig. 1.23 illustrates that certain paths, in particular those between A and D, A and H, and D and L,

are traversed more frequently than others. Since most of these points are at a fair distance from one another, the

diagram suggests that critical examination is called for, with a view to moving the work points which they represent

closer together.

The string diagram is a useful aid in explaining proposed changes to management. If two diagrams are made, one

showing the original layout and one the improved layout, the contrast is often so vivid that the change will not be difficult

to sell. The workers may especially are interested in seeing the results of such studies and discovering how far they

have to walk.

Travel Chart: It is a fact that the string diagram is a very neat and effective way of recording for critical examination of

the movement of workers and material, especially when readily understood before and after models is needed to help

in presenting the merits of the proposed changes. However, string diagram takes very long time to construct and even it

will become crowded when there is great many movements with many crossings. In such instances, travel chart is a

quicker and more manageable recording technique.

Even flow diagrams become particularly not suitable when inter-departmental and inter-section movement exists and

when quantities factors such as distances, weight and frequency of movement have to be studied. Even in this instance,

travel chart become useful.

Travel chart is a tabular record for presenting quantitative data about the movements of workers, materials or equipmentbetween any numbers of places over any given period of time.

Fig. 1.24 shows a travel chart which records the movements of a messenger delivering papers or information to the

various desks and workstations in an office. The layout of the office, showing the relative positions of the workstations is

also shown in the figure. Each square in travel chart represents a workstation that is, a place visited by the passenger

in this example. There are 10 stations and so the travel chart containing 10 x 10 squares to represent FROM TO

distances or frequency.

Figure shows the frequency of movement of the messenger from each station and also to station. Left and just below the

cross chart represent the summary of the frequency, i.e. summary to present FROM and TO movement, by adding

vertical columns and horizontal rows separately. Summary can also be replaced by bar chart for further illustration.

These charts not only provide an at-a-glance picture of volume and the nature of the movement to and from each station

or department, but also the form the basis for further investigation.

An examination of the chart shows that 10 journey have been made into station 2, 07 into station 9, and 06 into station 5.

These are the busiest stations. A scrutiny of the body of the chart helps to confirm this: there were 06 journeys from

station 2 to station 9, and 05 from station 5 to station 2. So, the busiest route is 5-2-9.

This suggests that it would be better to locate these stations next to each other. It might then be possible for the clerk at

station 5 to place finished work directly into the in-tray at station 2, and the clerk there to pass his or her work on to

station 9, thus relieving the messenger of a good deal of travelling.

If the squares marked by distance (total or unit distance alone with frequencies) or weight (total or unit), a better and

realistic picture could be obtained.


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Fig. 1.24: Travel Chart for Movement of Messenger in Office


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Idle

Types the Letter

Goes toManager's Office

Goes back to

Office

Type the Letter

Separate Copies

Goes toManager's Office

Types the

EnvelopIdle

Idle

Type Envelop,

Insert Letter &Place it Inside

Check & Sign

Letter Dictated

Idle

Idle

Idle

Typewriter Manager Typist

05

20

15

10

25

Cycle Graph and Chrono-Cycle-Graph: This technique was originated by Gilberth to record short motion patterns on a

photograph. The record can be made as continuous line which is known as cycle-graph. The record can be made as

dotted line which is known as chrono-cycle-graph.

Cycle-graph is made by attaching small lights to the workers wrists and making a time exposure while a single cycle or

portion of cycle is performed. The camera shutter is then closed after which a normal instantaneous exposure is made

on the film. Chrono-Cycle-graph is made by a similar procedure in which the light source is suitably interrupted so that

the path appears as a series of dots. This enables both the direction of movement and the speed at any point along the

path to be recorded.

These methods of recording are very expensive and are rarely used nowadays. They also have limited applications.

Multiple Activity Chart: This uses time scale to represent the time associated with activities. This type of chart is

extremely useful in organizing teams of operatives on mass-production, maintenance and similar work. In maintenance,

this is particularly useful when expensive plant can not be allowed remain idle longer than absolutely necessary. It can

also be used to determine the number of machines which an operator should be able to look after during a specified

time.

In making a chart, the activities of the different operatives and the machines are recorded in terms of working time and

idle time. These times may be recorded by ordinary wristwatch or by stop-watch, according to the duration of the various

periods of work and idleness. Extreme accuracy is not required, but timing must be accurate enough for the chart to beeffective.

It will be seen from the example given in Fig. 1.25, which shows writing a letter discussed in Fig. 1.13. It can be realized

that unlike the process chart, it displays only working time and non working time in respect of operators (typist &

manager) and typewriter.

Fig. 2.25: Multiple Activity Chart for Letter Typing

Fig. 1.26 and Fig. 1.27 show another example, where multiple activity charts have been prepared for the inspection

operation of catalyst in a converter with the original and improved process. It is worth to note that the idle time has been

reduced drastically in the improved process.


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Fig. 1.26: Multiple Activity Chart for Inspect of Catalyst (Original Method)

Fig. 1.27: Multiple Activity Chart for Inspect of Catalyst (Improved Method)


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Simo Charts (Simultaneous Motion Cycle Charts): Simo charts are used in micro-motion study. In certain types of

operation, and particularly those with very short cycles which are repeated many times over, it may be worth while going

into much greater details to determine where movements and effort can be saved and to develop the best possible

pattern of movement., thus enabling the operative to perform the operation repeatedly with minimum of effort and

fatigue. This is known as micro-motion study.

In simo charts, special micro-motion symbols known as THERBLIG (=Gilbreht) were used in the study. They have now

been replaced by the use of Predetermined Motion Time Standard (PMTS) Charts. Both film and Video cameras can be

used to record activities at the work place. This permits advantages:

Greater detailing than eye observation Greater accuracy than pencils, paper and watch techniques More convenient Positive record Help in the development of the work study person themselves

(PMTS CHART WILL BE DISCUSSED LATER)

4.2.5 Evaluate Alternative Method

During the development stage, a number of possible changes to the existing method or a number of potential

developments may have highlighted. Some of them may be capable of immediate introduction, while others such as

introduction of new equipment, operator training, etc. may require further actions before implementation. Now, the

management need to take the decision for a preferred solution, for which information on alternative methods, the likely

results of the proposed changes and the implementation cost should available for managers. Therefore, a cost-benefit

analysis of each proposed method should be prepared.

At the beginning, very broad cost and benefits for each solution can be presented in order to glance through the

solutions for the purpose of excluding potential changes and for detailed evaluation. It is important to include benefits

that easily and quantitatively justified, but also to express in terms of qualitative terms such as job satisfaction, industrial

relations, moral that has long-term financial effect. Each solution can be weighted or rated with a common scale by

transforming qualitative benefits into quantitative benefits.

The nature of the evaluation depends on the nature of the situation under review and the scope and the scale of the

proposed changes. The findings of this evaluation phase are included in the project report, perhaps with a recommended

course of action, submitted to the management of the area under review. The report can also include implementation

plan, if a completely new method is proposed.

4.2.6 Define the Improved Method

Once the decision has been taken on the changed in method, it is important to define the method strictly. For all jobs

other than those performed on standard machine where the process and methods are virtually controlled by the

machine, it is desirable to prepare a written standard practice, also known as an improved instruction sheet. This

serves the following several purpose depending on the job:

It records the improved method for future reference, in as much details as may be necessary. It can be used to explain the new method to management, supervisors, and operatives. It also advises all

concerned of any new equipment required or of changes needed in the layout of machines or products.

It is an aid to training operatives and can be used by them for reference until they are fully conversant with thenew method.

It forms the basis on which time studies (i.e. work measurement) may be taken for setting standards, althoughthe breakdown by element will not necessarily be the same as the breakdown by notion.


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Such a written statement also outlines in simple terms the methods to be used by the operative. The following

information will normally be required:

The tools and equipment to be used and the general operating conditions. A description of the method. The amount of detail required will depend on the nature of the job. A diagram of the workplace layout and, possibly, sketches of special tools and fixtures.

Such statement may be supplemented by lay out diagrams, flow charts, process charts etc. to visualize the content.4.2.7 Install the Improved Method

Installation of the improved method is the most difficult part as it needs corporation from all levels management,

supervisors, workers, and unions. It is here that personal qualities of the work study person, his ability to explain clearly

and simply about the improvement is a gift for getting along with other people and their trust become the greatest

important.

Installation can be divided into stages:

Gaining acceptance fro management, supervisors and workers Preparing to make the changes Controlling the change over

The first factor has already been discussed. It is also important that the change-over from an existing method to a

revised one is properly planned. Main tasks such as purchasing, constructions, training, etc. should be identified before

implementation begins. Once the tasks are identified, they are scheduled to control each step of the implementation

process.

4.2.8 Maintaining the New Method

Once the new method is installed and operating satisfactorily, it does not necessarily continue to give benefits unless it is

maintained with effort. The conditions are liable to change from time to time, and this may mean that some of

assumption upon which the improved method was built up are no longer valid. The method should be reviewed at

intervals to make allowances for any changes. Changes can arise from three main reasons:

Deliberate and discernible alterations to method for good reason Changes as a result of suggestions schemes Minor innovations introduced by supervisors and workers

The method can be reviewed in regular intervals looking for above and the frequency will depend on the nature of the

work. The main purpose of such a review should be to disclose whether there are any discrepancies between the

authorized procedure and the current practice at the time of review.

4.3 Methods and Movements at the Work Place

This is the major area of the application of workstudy for enhancing the productivity of man and machines. So far, the

major focus was on separate activities involved with workers, machines and materials. Now, it has expanded to look at

one worker working at a workplace, bench or table and to apply the principles to worker and working place. Major

application areas of this type are assembly works in repetitive nature.

Such a working place design focus on movement of hands, fingers and body. Depending on the anthropometric data of

the body, the working area for a human body is changed. Fig. 1.28 shows the normal working area and the storage area

on the workbench for the average operative. As far as possible, materials should not be stored in the area directly in

front of the worker, as stretching forwards involves the use of the back muscles, thereby causing fatigue. This

arrangement is explored in principles of motion economy.


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Fig. 1.28: Normal and Maximum Working Area

4.3.1 The Principles of Motion Economy

There are number of principles concerning the economy of movements which have been developed as a result of

experience and which form a basis for the development of the improved method at the workplace. They are: Use of human body Arrangement of the work place Design of tools and equipment

They are useful in shops and office alike and, although they can not always be applied, they do form a very good basis

for improving the efficiency and reducing fatigue of manual work. The following description simplifies and explains the

approach.


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Use of Human Body: Whenever and wherever possible, the following should be fulfilled for the work at work place.

The two hands should begin and complete their movements at the same time. The two hands should not be idle at the same time except during the periods of rest. Motions of the arm should be symmetrical and perform simultaneously. Hand and body motion should be made at the lowest position at which it is possible to do the work satisfactorily. Momentum should be employed to help the worker, but should be reduced to a minimum whenever it has to be

overcome by muscular effort.

Continuous curved movement are to be preferred to straight line motions involving sudden and sharp changesin direction.

Ballistic (i.e. free-swinging) movements are faster, easier and more accurate than restricted or controlledmovements.

Rhythm is essential to the smooth and automatic performance of a repetitive operation. The work should bearranged to permit natural rhythm whenever possible.

Work should be arranged so that eye movements are confined to a comfortable area without the need forfrequent changes of focus.

Arrangement of the Workplace: Whenever and wherever possible, the following conditions should be fulfilled in

designing the work place.

Definite and fixed stations should be provided for all tools and materials to permit habit formation. Individual tools and materials should be pre-positioned to reduce searching. Gravity feed, bins and containers should be used to deliver materials as close to the point of use as possible. Tools, materials and controls should be located within the maximum working area and near to the worker as

possible.

Materials and tools should be arranged to permit the best sequence of motions. Ejectors should be used wherever possible, so that the operator does not have to use his/her hands to dispose

of the finished work.

Provision should be made adequate lighting, and a chair of the type and height to permit good posture shouldbe provided.

The height of the workplace and seat should be arranged to allow alternate standing and sitting. The colour of the workplace should contrast with that of the work and thus reduce eye fatigue.

Design of Tools and Equipment: Whenever and wherever possible, the following tools and equipment should be

provided for convenience of working.

The hands should be relieved of all work of holding the work piece where this can be done by a jig, fixture orfoot-operated device.

Two or more tools should be combined wherever possible. Where each finger performs some specific movement, as in typewriting, the load should be distributed in

accordance with the inherent capacities of the fingers.

Handles such as those on cranks and large screwdrivers should be so designed that as much of the hand aspossible can come into contact with the handle. This is especially necessary when considerable force has to be

used on the handle.

Levers, crossbars and hand wheels should be so placed that the operative can use them with the least changein the body position and the greatest mechanical advantage.


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In design of work place, it is accepted norm to keep any movement to lowest class, which is finger movement around the

knuckle that gives lowest fatigue. The following gives the different class of such movement;

Class Pivot Body Movements

1. Knuckle Finger

2. Wrist Hand, Fingers

3. Elbow Forearm, hand, fingers4. Shoulder Upper arm, forearm, hand, fingers

5. Trunk Torso, Upper arm, forearm, hand, fingers

In addition to body movement, the following can be considered as important in such design:

If similar work is being done by each hand, three should be a separate supply of materials/parts for each hand. If the eyes are used to select the material, as far as possible, the material should be kept in an area where eyes

can locate it without there being any need to turn the head.

Use semi-circular arrangement in preference to circular arrangement as in Fig. 1.29.

Design the workplace using ergonomics principles. A recommended posture for sitting is shown in Fig. 1.30. The nature and the shape of the material influence its position in the layout. Various bins shown in Fig.1.31 can

be used to accommodate different nature of material.

Hand tools should be picked up with the least possible disturbance to the rhythm and symmetry of movements. Tool should be easy to pick up and replace; as far as possible they should have an automatic return. (Fig. 1.32). Finished work should be dropped down with least hand and eye movement. If the operation is intermediate one,

placed in a container in such a way that next operator can pick it up easily.

Two-Handed Process Chart: As discussed previously, the work limited to single work place often involves of using both

hands and arms only. In this situation, two-handed process chart can be drawn to represent the sequence of activities of

the worker. Therefore, the two-handed process chart is a process chart in which the activities of a workers hand (orlimbs) are recorded in their relationship to one to another. Sometimes time scale is too added to the chart. One

advantages of incorporating a time scale in the chart form is that the symbols for what the two hands are doing at any

given moment are brought opposite each other. It is usually is used for repetitive operations, when one complete cycle

of the work is to be recorded.

It generally employs the same symbols as the other process charts; however, because of the greater details covered, the

symbols are accorded slightly different meaning (Refer Fig. 1.33).

Example given in Fig. 1.34 describes how a two-handed process chart was constructed for cutting a glass tube with a

help of jig.


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Fig. 1.29: Circular and Semi-Circular Working Arrangement

Symbol Name Description

OPERATION Activities such as grasp, position, use, release etc..

TRANSPORT Movement of the hand from or to the work, material, tool

DELAY Hand is in idle position without having specific task

HOLD Holding the work, materail or tool

Fig. 1.33: Two-Handed Process Chart Symbols


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Fig. 1.31: Various Bins and Motion Economy Devices


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Fig. 1.34: Two-Handed Process Chart for Ball-Point Assembly

Reference:

Introduction to Work Study, ILO Publication

Documents

OUR-EnG Workstudy 1