Work study

PRODUCTION AND
OPERATIONS
MANAGEMENT
Chapter 10
DESIGN OF WORK SYSTEMS

Design of Work Systems
Work Study-Method Study and Work
Measurement
• Methods engineering includes work simplification, job
design, value analysis and the like.
• Work study method was developed to improve performance
of a given work.
• Work study is the body of knowledge concerned with
analysis of the work methods, and the standard of proposed
work methods.
• Objective of work study is to improve operational
efficiency.
• The purpose of work study is to determine the best or most
effective method of accomplishing a necessary operation.

Relationship of Time and Motion
Study to Work Study
• Time study and motion study are results of
practices developed by F.W. Taylor, Frank and
Lillian Gilbreth.
• Time study: Exercising control over the output in
respect of a job by setting standards for
performance.
• Time study may be used to compare the
effectiveness of alternative work methods.

Design of Work SystemsSteps Involved in Work Study

Method Study or Methods Analysis
• Method study is also known as methods improvement.
• Prime objectives of method study is to eliminate wasteful
and inefficient motions.
• It is a scientific technique of observing, recording and
critically examining the present method of performing a
task or job or operation with the aim of improving the
present method and developing a new and cheaper
method.
• It encompasses study of work processes, working
conditions and equipment. tools used to carry out the job.

Objectives of Method Study
• To study existing proposed method of doing a job.
• To develop an improved method to improve
productivity and reduce operating cost.
• To reduce excessive material handling or
movement so reduce fatigue to workmen.
• To improve utilization of resources.
• To eliminate wasteful and inefficient motions.
• To standardize work method, processes, working
conditions, machinery, tools etc.

Method Study Procedure
 Method study procedure involves six steps.
• Select: select the job and define the objective for
selecting this particular job for study.
• Record: all relevant information.
• Examine: recorded fact critically examined.
• Develop: generating several alternatives and selecting the
best method in terms of cost of implementation, expected
savings in time and cost, feasibility, productivity,
acceptance to design, ppc, quality control and sales
departments etc.
• Reaction of employees for new method.
• Short term or long term implication of alternatives.
• Install: in 3 phases- planning, Arranging and
implementation.
• Maintain: ensure the installed method functioning well.

Recording Techniques Used in
Method Study
 Process Charts used in Method Study
1. Outline process chart
2. Operation process chart
3. Flow process charts
4. Two handed process chart
5. Multiple activity chart
6. The man machine chart or worker-machine chart
7. Flow diagram
8. String diagram
9. SIMO chart

Qualified Worker
"A qualified worker is one who is accepted as having the
necessary physical attributes, possessing the required
intelligence and education and having acquired the
necessary skill and knowledge to carry out the work in
hand to satisfactory standards of safety, quantity and
quality"

Work Measurement
• Measuring the work content of any activity under this study.
• Work measurement is defined as the application of
techniques designed to establish the work content of
specified task by determining the time required for carrying
out the task at a defined standard of performance by
qualified worker.
• According to ILO-it is defined as the technique applied to
determine the amount of time necessary for a qualified
worker to perform a particular task.

• Standard time: is the amount of time a
qualified worker working at a normal rate
of sped, will require to perform the
specified task.

Techniques of Work Measurement
 The main techniques used to measure work are:
1. Direct Time Study.
2. Synthesis Method.
3. Analytical Estimating.
4. Pre determined Motion Time System (PMTS).
5. Work sampling or Activity Sampling or Ratio
Delay Method.

Steps in Work Measurement
 Work measurement involves seven steps.
1. Break the job into elements
2. Record the observed time for each element by means of either time
study, synthesis or analytical estimating.
3. Establish elemental time values by extending observed time into
normal time for each element by applying a rating factor.
4. Assess relaxation allowance for personal needs and physical and
mental fatigue involved in carrying out each element.
5. Add the relaxation allowance time to the normal time for each
element to arrive at the work content.
6. Determine the frequency of occurrences of each element in the job,
multiply the work content of each element by its frequency (i.e.,
number of time the element occurs in the job) and add up the times
to arrive at the work content for the job.
7. Add contingency allowance if any to arrive at the standard time to
do the job.

1. TIME STUDY
• Time study is concerned with the determination of the
amount of time required to perform a unit of work.
• Objective of time study is to establish the standard time.
• Time study by stop watch: The steps involved are
1. Select the job to be studied
2. Select the worker to be studied
3. Conducting stop watch time study

2. SYNTHESIS METHOD
Synthesis Method: Building up the time required to do a
job at a defined level of performance.
3. ANALYTICAL ESTIMATING
Analytical Estimating: Used to determine the time
values for jobs having long and non-repetitive
operations.
4. PREDETERMINED MOTION TIME SYSTEM
(PMTS)
PMTS: Normal times are established for basic human
motions.
5. WORK SAMPLING OR ACTIVITY SAMPLING OR
RATIO-DELAY METHOD
Work sampling helps determine allowances for inclusion
in standard times.

The work sampling study consists of essentially the following steps:
1. Determine the objective of the study, including definitions of the
states of activity to be observed.
2. Plan the sampling procedure including:
(a) An estimate of the percentage of time being devoted to each
phase of the activity.
(b) The setting of accuracy limits.
(c) An estimation of the number of observations required.
(d) The selection of the length of the study period and the
programming of the number of readings over this period.
(e) The establishment of the mechanics of making the
observations, the route to follow and the recording of data.
3. Collect the data as planned.
4. Process the data and present the results.

Motion Study
 Motion study is the science of eliminating
wastefulness resulting from using unnecessary; ill-
directed and inefficient motion. The aim of motion
study is to find and perpetuate the scheme of least
waste methods of labour.
 Micro motion study provides a valuable technique
for making minute analysis of those operations that
are short in cycle, contain rapid movements and
involve high production over a long period of time.
 Micro-motions are also known as ‘Therbligs’.

Examples of Therbligs
1. Search (Sr)
2. Select (St)
3. Grasp (G)
4. Transport empty
(TE)
5. Transport loaded
(TL)
6. Hold (H)
7. Release load (RL)
8. Position (P)
9. Pre-position (PP)
10. Inspect (I)
11. Assemble (A)
12. Disassemble (DA)
13. Use (U)
14. Unavoidable delay (UD)
15. Avoidable delay (AD)
16. Plan (Pn)
17. Rest for overcoming fatigue
(R)
18. Find (F)

Principles of Motion Economy
Principles of motion economy are divided into
three groups.
a. Effective use of the operator
b. Arrangement of the workplace
c. Tools and equipment

Productivity and Employees
• Production refers to the total output.
• Productivity: The amount of goods and services
produced with resources used.

Output in a given period
• Partial productivity: Output in a given period divided
by labors hours used in the period.
Labour hours used in the period
Partial productivity =
Total productivity =
Output in a given period
Labour + Capital + Materials + Energy used
in the same period

• Labour Productivity
There are three ways of measuring labour
productivity.
• Ways of Improving Productivity
Understanding the factors that influence the
relationship between output and input.

Work study

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