Lecture9,10,11

Unit 2

Chapter 2.1

Work study

• Work study may be defined as systematic examination of methods of carrying on activities so as to improve the effective use of manpower and equipment and to set up standards of performance for the activities being performed.

• Work measurement or time study 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.

Work study

Components of Work Study

• Why use it ? - Productivity - Improving equipment utilization - Conserving materials and energy - Reducing human effort - Advancing the goals of the organization on

many fronts• Changes may be small, but improvements must

be made continually to keep the company competitive.

• Quality and price are the most important considerations for staying competitive

• Motion and time study concentrate on reducing cost but must never lost sight on quality

1. Develop the best work method and efficient utilization of man, machine & methods.

2. Comparative evaluation of performance3. Develop economical and efficient tools, fixtures, and

production aids.4. Assist in the selection of new machine and equipment5. Train new employees in the preferred method6. Reduce effort and the unit cost of production.7. Efficient panning for production.

Objective of Motion and time studies :

1. Definitions• Motion study involves the analysis of the basic hand, arm,

and body movements of workers as they perform work.

• Work design involves the methods and motions used to perform a task.

• This design includes – the workplace layout and environment– the tooling and equipment (e.g., work holders, fixtures,

hand tools, portable power tools, and machine tools). • work design is the design of the work system.

Method/Motion Study and work simplification

• Selection of the work to be studied.• Collection of Data and recording of relevant facts

about the existing method.• Critical and impartial examinations of the data

collected( table 1).• Development of the best method .• Installation of the new method• Maintaining the new method.

(Table 1) Critical examination questions

• Purpose – What, Why, What else might & Should

be done ?• Place

– Where, Why, Where else & Where should it be done ?

• Sequence– When, Why then, When else could &

When should ?• People

– Who, Why, Who else might & should do it?

• Method or Means– How, Why, How else could, How else

should

a sound reason for every activity

no assumptions so double check

quality, safety and health must not compromised

a sound reason for every activity

no assumptions so double check

quality, safety and health must not compromised

Method Study

2.Work Simplification

• Work simplification is defined as the use of equipment , ergonomics, functional planning and behavior modification to reduce the physical and psychological stresses on the body of activities at home or work . These can be broadly classified as:-

1. Modifying the workplace layout and equipment.2. Modifying the loads lifted3. Controlling the work environment4. Redesigning work practices

2.1 Work simplification is carried out with the help of various charts and diagrams

• Process charts:- outline process charts, Two handed Process charts, Flow Process charts

• Flow diagram• String Diagrams• Multiple Activity chart

2.3 Principles of Motion Economy

Principles of motion economy provides guidelines to help determine work method, workplace layout, tools and equipment . The objective of this principle is to maximize efficiency and minimize worker fatigue . The principles of motion economy eliminate wasted motion , ease operator tasks and reduce fatigue There are 3 categories of principles:-

1. Principle that apply to the use of the human body2. Principles that apply to the workplace arrangement( workplace

layout)3. Principles that apply to the design of tooling and equipment.

2.2 Process Charting

3.Work Measurement or Time Study

• Time study attempts to find out the amount of work that a qualified operator , properly trained , can do in a given time . The operator must do the work according to a certain method , under certain conditions , and at certain pace which will produce a certain physical reaction.

• Performance Rating is a technique for equitably determining the time required to perform a task by the normal operator after the observed values of the operation under study have been recorded.

• Allowance Factor is addition o an allowance to take care of the many interruptions , delays , and slowdowns brought on by the fatigue , which enter into every work assignment.

Importance and Uses of Time Study

• No. of machine tools needed• No. of production personnel needed • Manufacturing costs and selling prices• Scheduling and delivery criteria• Machine speeds and work balancing• New equipment purchases• Incentive wages

3.1 Stopwatch Time Study

May use various stopwatches-read in decimal minutes. Continuous time study- short duration jobs Long-cycle time study-long jobs, or when work elements out-of -sequence

3.2 Performance Rating

It is the procedure in which the time study engineer compares the performance of operators under observation to the normal performance and determines a factor called Rating Factor

Rating Factor=Observed performance/ normal performance

3.3 Allowances

1. Daily allowance2. Fatigue allowance3. Personal allowance4. Special allowance