- by Prashant Prajapati

What is WORK STUDY ?

Pyramidal Structure of Work

Work Study is the systematic examination of the methods of carrying out activities such as to improve the effective use of resources and to set up standards of performance for the activities carried out. A generic term for those techniques, particularly method study and work measurement, which are used in the examination of human work in all its contexts, and which lead systematically to the investigation of all the factors which affect the efficiency and economy of the situation being reviewed, in order to effect improvement.

Work Study

Method Study

Work Measurement

METHOD STUDY?

Method-study concerned with the way in which work is done (i.e., method). It is used to simplify the way to accomplish a work and to improve the method of production. Method-study results in a more effective use of material, plant, equipment and manpower.

Method study is essentially concerned with finding better ways of doing things. It adds value and increase the efficiency by eliminating unnecessary operations, avoidable delays and other forms of waste. The improvement of efficiency is achieved through: 1.Present and analysis true facts concerning the situation. 2.To examination those facts critically. 3.To develop the best answer possible under given circumstances based on critical examination of facts.

Steps or procedure involved in methods study

1. Select : select the work to be studied. The job should be selected for the method study based upon the following considerations: a) Economical aspect b) Technical aspect c) Human aspect

2. Record: record the relevant facts about the job by direct observation Recording techniques used for method study are charts and diagrams.

Recording techniques for method study

Charts Diagrams 1. Flow Diagram 2. String Diagram

Macro Motion Charts 1. Operation Process Chart 2. Flow Process Chart 3. Two Handed Process Chart 4. Multiple Activity Chart

Micro Motion Charts

Recording techniques for method study

Operation process chart: An operation process chart provides the chronological sequence of all operations and inspections that occur in a manufacturing or business process. Operation process chart used only two symbols, i.e., operation and inspection.

Operation

Move

Delay

Store

Inspection

Combined Activity

Cut to length

Deburr

Inspect

Electroplate

Flow process chart: A flow process chart is used for recording greater detail than is possible in an operation process chart. It is made for each component of an assembly rather than for the whole assembly.

String Diagram: String Diagram is a scale layout drawing on which, length of a string is used to record the extent as well as the pattern of movement of a worker working within a limited area during a certain period of time. It is a scale diagram on which color threads are wrapped around pins or pegs, which are used to indicate the paths taken by either worker or material or equipment when processing is done on material from start to finish.

Example : A metal worker became fed up with walking what seemed to be half-way around the machine room just to build a metal box. With help from the works facilitator, he measured the distance he travelled to build one box, using a pinboard and scale map of his workshop area, as below. Using this, he simply moved the machines into a U-shape. the result was an easier and faster process, which also used less floor space.

3. Examine: examine the way the job is being performed and test its purpose, place, sequence and method of performance. Like, what is done?, why it is done?, what else might be done? Etc. A view to eliminate, combine, rearrange and/or simplify the activities.

4. Develop: develop the most practical, economical, and effective method. After critical examination of records is complete, it is necessary to transform the learnings into the development of new methods. Some approaches are: a) Eliminate unnecessary activities.

b) Combine two or more activities.

c) Re-sequence activities so as to reduce time and effort. d) Simplify process e) Attack on constraints, which are preventing the method to perform better.

WORK MEASUREMENT

Work measurement is the application of techniques designed to establish the time for a qualified worker to carry out specified jobs at a defined level of performance or at a defined rate of working.

Uses of work measurement: To compare the efficiency of alternative methods.

Cost estimation

Pricing of products and services

Incentive pay systems

Capacity planning

Production scheduling

To provide information on which estimates for tenders, selling prices and delivery promises can be based.

Technique of work measurement:

a) Time study: short cycle repetitive jobs

b) Work sampling: Long cycle jobs

c) Predetermined motion time standards: Manual operations confined to one work centre.

Task Hierarchy Level Work measurement Technique

Job Level

Task Level

Work Element Level

Basic motion element Level

Working Sample

Direct time study, Standard data system

Working Sample

Time Study

Steps in making a time study 1) Select the work to be study

The job is a new one not previously carried out. A change in material or method of working has been made and a new time standard is required. A complaint has been received about the time standard for an operation. A particular operation appears to be bottleneck holding up the subsequent operations and possibly previous operations. Standard times are required prior to the introduction of an incentive scheme.

2) 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. 3) Breakdown the operation into elements.

4) Measure the time by means of a stop watch taken by the operator to perform each element of operation. Either continuous method or snap back method of timing could be used. 5) At the same time assess the operators effective speed of work relative to the observers concept of normal speed. This is called performance rating. 6) Adjust the observed time by rating factor to obtain normal time (basic times) for each element. 7) Sum the normal times for each element to develop a total normal time for the task 8) Determining the allowances to be made over and above the normal time for operation. 9) Determining the standard time for the operation. 10) Test and review standards wherever necessary.

Personal time allowance : 4% - 7% of total time - use of restroom, drinking water, etc. Fatigue allowance - to compensate for physical or mental strain, noise level, tediousness, heat and humidity, assumption of an abnormal position, etc. Delay allowance - based upon actual delays that occur.

Observed Time

Normal Time Standard

Time

Allowance Fraction

Performing Rating

Standard time = observed time + rating factor + Personal allowance + Fatigue allowance + delay allowance + work related contingency allowance.

Observed time = 8.6 minutes Performance rating = 0.95 Allowance fraction = 0.125 Find the standard time Normal time = Observed time x Performance rating Standard Time = Normal time / (1 Allowance fraction)

MOTION STUDY

Motion study is a technique of analyzing the body motions employed in doing a task in order to eliminate or reduce ineffective movements and facilitates effective movements. By using motion study and the principles of motion economy the task is redesigned to be more effective and less time consuming. Objective of motion study is job simplification so that it is less fatiguing and less time consuming. Lillian Gilbreth used motion picture to study worker motions developed 17 motions called therbligs that describe all possible work. Traditionally, the data from micro motion studies are recorded on a Simultaneous Motion (simo) Chart while that from macro motion studies are recorded on a Right Hand - Left Hand Process Chart.

1. Transport empty (TE) reach for an object 2. Release load (RL) release control of an object 3. Pre-position (PP) position object for next operation 4. Position (P) position object in defined location 5. Disassemble (DA) separate multiple parts that were previously joined 6. Search (Sh) attempt to find an object using eyes or hand 7. Select (St) choose among several objects in a group 8. Plan (Pn) decide on an action 9. Unavoidable delay (UD) waiting due to factors beyond worker control.

10. Grasp (G) grasp an object 11. Use (U) manipulate a tool

12. Transport loaded (TL) move an object with

hand and arm.

13. Hold (H) hold an object

14. Assemble (A) join two parts

15. Inspect (I) determine quality of object

16. Avoidable delay (AD) worker waiting

17. Rest (R) resting to overcome fatigue

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