After reading this article you will learn about:- 1. Definition and Concept of Work Study 2. Need for Work Study 3. Advantages.
Definition and Concept of Work Study:
Work study, as defined by British Standard Institution, is 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 effect the efficiency of the situation being reviewed, in order to seek improvements.
Actually, work study investigates the work done in an organisation and it aims at finding the best and most efficient way of using available resources, i.e., men, material, money and machinery. Every organisation tries to achieve best quality production in the minimum possible time.
The time required to manufacture an item depends upon the manufacturing procedure; and one phase of work study known as Method study aims at finding the best possible manufacturing procedure which involves, least time and does not cause fatigue to the workers.
In brief, method study or motion study aims at finding the best way of doing a job. Method Study may be defined as the systematic investigation (i.e., recording and critical examination) of the existing method of doing a job in order to develop and install an easy, rapid, efficient, effective and less fatiguing procedure for doing the same job and at lower costs.
This is generally achieved by eliminating unnecessary motions involved in a certain procedure or by changing the sequence of operation or the process itself.
Once the method study has developed an improved procedure for doing a job, the work Measurement or Time Study will find the time allowed to complete the job by that procedure. Work Measurement may be defined as the application of different techniques to measure and establish the time required to complete the job by a qualified worker at a defined level of performance. The time necessary to complete a job is determined from number of observations.
Need for Work Study:
Principles of work study used to be employed even long ago, in order to explore improvements, when industry was simple and involved lesser problems; of course a systematic procedure was not there. Today the industries with all their complexities and modernization naturally demand a more systematic approach like the work study in its present form.
Work study finds applications in:
1. Industries (Production operations, research and development),
2. Marketing, sales and distribution,
3. Offices, stores and warehouses,
4. Material handling,
6. Building and other constructions,
9. Army, and
10. Agriculture, etc.
Advantages of Work Study:
(a) Uniform and improved production flow,
(b) Higher productive efficiency,
(c) Reduced manufacturing costs,
(d) Fast and accurate delivery dates,
(e) Better employee-employer relations,
(f) Better service to customers,
(g) Job security and job satisfaction to workers,
(h) Better working and other conditions, and
(i) Higher wages to workers.
Objectives of (or Advantages Obtained Through) Method Study:
(1) Improved working processes and standardized procedures,
(2) Better work place layout; neat and clean environments and working conditions,
(3) Less fatigue to operators,
(4) Better product quality,
(5) Effective utilization of men, materials and machinery,
(6) Efficient and fast material handling,
(7) Reduced health hazards,
(8) Efficient planning of the section, and
(9) Streamlined working procedures.
Objectives of (or Advantages Achieved Through) Work Measurement:
(1) Determines the time required to do a job; thus it compares alternative methods and establishes the fastest method;
(2) Decides man power required for a job; it helps in man power economy;
(3) Decides equipment requirements;
(4) Provides information for effective production planning and maintenance procedures;
(5) Aids in calculating exact delivery dates;
(6) Decides realistic labour budgeting and provides a basis for standard costing system;
(7) Provides a basis for fair and sound incentive schemes; and
(8) Results in effective labour control.
Irrespective of the advantages mentioned above, the introduction of work study has always been looked by the supervisors, workers or union with suspicion. They probably feel insecure and think that work study will result in reduction in their salaries. Even otherwise a sudden change is never appreciated therefore workers and union should be taken into confidence and properly convinced before introducing work study.
Operation Analysis is a detailed study of different operations involved in doing a work. Operation analysis becomes necessary in order to investigate the shortcomings of the existing method and to develop an improved procedure.
Operation analysis suggests, whether some elements, should be eliminated or combined or their sequence should be altered in order to obtain effective utilization of existing manpower and machinery with the minimum fatigue incurred by the workers. The analysis mainly considers the movements of the limbs and aims at finding a simpler and economical method of doing the job.
Before the procedural steps of a task are analyzed and the motions (of an operator) are studied or eliminated, an operation chart is constructed. Figure 9.7 shows an operation chart of the existing method of assembling nuts and bolts.
As a next step, the different motions involved are subjected to specific and detailed questioning with a view to eliminate unnecessary motions, and to arrange the remaining motions in a better sequence. Principles of motion economy serve as a very good guide in developing a better and improved method.
The chart (Fig. 9.7) of the existing method is tested as per the rules of motion economy and the following points are noted:
(1) The distribution of work between the two hands is not balanced. Right hand is overloaded.
(2) The two hands do not follow opposite motions.
(3) Gravity has not been utilized for delivering the material to its destination, etc.
Besides assessing the present method a per the principles of motion economy, it is also subjected to following questions (whichever are applicable) with regard to:
1. Is he mentally and physically fit?
2. Does he incur unnecessary fatigue?
3. Does he need training to improve?
4. Does he get suitable salary?
1. Are tools and other equipment readily available?
2. Can the set-up be modified or can the number of set-ups be decreased?
1. Is material of the proper specification i.e., composition, diameter, width, thickness of weight?
2. Can it be substituted by a less costly material?
3. Can scrap be minimized?
(d) Material Handling:
1. Can materials be transferred in big (unit) lots, thereby reducing the number of handlings?
2. Is it possible to avoid back tracking of the material?
3. Can the distances, by which the material is moved, be cut short?
1. Can some operations be eliminated?
2. Can some operations be made automatic?
3. How, re-sequencing of the operations will effect?
4. Is it possible to combine some operations?
(f) Tools and Fixtures:
1. Are they available in good condition?
2. Are they suitably located and prepositioned?
3. Is it advantageous to modify existing jigs and fixtures for better productivity?
(g) Working Conditions:
1. Is light and ventilation adequate?
2. Are the operations and working conditions safe?
3. Are facilities of wash rooms, etc., available?
Considering the existing method in the light of motion economy principles and questions mentioned above, a proposed method for the same task is as follows (Fig. 9.8).
Analysis of Motion:
The motions or movements of the limbs of a worker play a major part in the fabrication or manufacture of the products. By carefully observing a worker while he is doing an operation, a number of movements made by him which appear to be unnecessary and unproductive can be identified and eliminated.
Analysis of an operation, when carried out in terms of individual motions of a worker is known as motion analysis.
The purpose of motion analysis is to design an improved method which eliminates unnecessary motions and employs human efforts more productively. In doing so the principles of motion economy prove to be very helpful.
Steps involved in Motion Analysis are:
(a) Select the operation to be studied.
(b) List and chart various motions performed by the operator.
(c) Identify the productive and idle motions.
(d) Eliminate the unnecessary and non-productive motions.
(e) Redesign the existing operating procedure by employing minimum number of motions in the most appropriate sequence and in accordance with the principles of motion economy.
(f) Impart necessary instructions to the worker so that he develops proper habit cycle.
(g) Check once again the procedure in the light of step (e) above.
(h) The procedure may be standardized.
Therbligs were suggested by Gilbreth. Therbligs are used to describe the basic elements of movements or fundamental hand motions of the work cycle. Every therblig is represented by a symbol, a definite colour and with a word or two to-record the same. For example, thereblig Grasp has symbol U, red colour and is denoted by the word G. A simo chart employs therbligs which are of microscopic nature, whereas a process chart uses symbols like operation, inspection, transportation, etc., which are macroscopic. A single operation may consist of many therbligs; for example,
Though it looks cumbersome to deal with and to chart microscopic motions, yet they possess decided advantages over macroscopic motions.
1. One macroscopic motion may contain a number of microscopic motions. At times, it may not be possible to eliminate completely a macromotion but an unnecessary micromotion can definitely be avoided.
2. Since microsystem is very detailed, it is simpler to understand what precisely the worker is doing.
3. Therblig colours make the charts more meaningful.
Various Therbligs along with their definition, symbols and colours are given below: