Work Study

Work Study

30th October, 2007

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What is work Study  Work Study is defined as process which is used to examine human work in all its contexts.  It leads to systematic investigations of all factors which effect the efficiency of situation being reviewed To Seek Improvements

 It aims at finding the best and efficient way of using : Men , Material, Money & Machinery 2

Elements of Work Study  Method and Motion Study:  Systematic investigation of existing method in order to develop and install an easy ,rapid ,efficient , effective and less fatiguing procedure for doing same job at lower costs.  Done by eliminating unnecessary motions, alteration of sequence in a process or alteration of process itself

 Work Measurement  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

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Work Study – Advantages & Applications  Advantages:  Unfiform and improved production flow  Higher productive efficiency  Reduced manufacturing costs  Fast and accurate delivery dates  Better Wage setting procedures

 Applications of Work Study:  Industries ( production operations,research and development)  Marketing,sales and distribution  Offices,stores and warehouses,  Material handling  Building and constructions  Hospitals and army and agriculture.

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Method Study - Procedure  Select and set objectives: 

To reduce manufacturing cost



Reduce bottle neck



Increase operator efficiency

 Record all data pertaining to existing method by: 

Process Charts : 1. Flow process chart 2. Two handed process chart 3. Multiple activity chart



Flow Diagrams



Models



Motion and film analysis: 1. Simo chart - Simultaneous Motion Chart

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Flow Process Charts for Data Recording This chart uses

This chart is of 3 types:

circles for operations

 Man – Activities of operator

arrows for transports squares for inspections  triangles for storage letter D for delays.

 machine - Manner in which the equipment is used  Material - the changes the material undergoes in location or condition

Before Layout Revision Sl. No . 1

Operation

M achine

Storage

From In trolley

2

Coining

Press

3

Storage + Relief Plug Assy.

Trolley

4

Ball Pressing

Press

5

Storage

On the Machine

6

Leak Check

Air Gauge

7

Storage

Table

8

Poppet assembly

Table

9

Bearing Pressing

Press

10

Storage

Table

11

Thrust washer Assy.

Poka-Yoke

12

Storage

--

Total

Process

After Layout Revision Sl. No.

Operation

Machine

1

Storage

In trolley

2

Coining

Press

3

Bearing Pressing

Press

4

Ball Pressing

Press

5 6

Leak Check& Poppet Assy. Thrust washer Assy.

Total 6

6

0

1

Process

Table PokaYoke 1

5

0

0

0

4

Vertical lines connect these symbols in the sequence they are performed.

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Two handed Process Charts for Data Recording

Two handed process chart records the activities of left and right hand as related to each other • Use of human body • 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 periods of rest • Motions of the arms should be symmetrical,in opposite direction and simultaneous • Continuous curved movements are to preferred to straight line motions involving sudden and sharp,changes in direction • Work should be arranged so that eye movements are confined to a comfortable area, without the need for frequent changes of focus

Process Left hand Operation

LH

RH

Right hand Operation

Pick up Bolt

Idle

Hold

Pick up Nut

Hold

to left hand

Hold

assemble

Summary of Saving Activity

LH

RH

Operation

1

2

Transport

0

1

Check ing

0

0

Storage

3

1

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Multiple Activity Charts for Data Recording This chart records simultaneously the activities of all the workers and machine on a common time scale and shows inter- relations between them To detect idle times and to decide no. of workers To balance work team and optimize work distributions between workers

Applications:  Plant repair and maintenance  Planning team work

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Flow Diagram for Data Recording Flow Diagram depicts the probable movement of materials in the floor plant. The movement is represented by a line in the plant drawing.  This chart indicates the movement of men and materials  If these movement are reduced it will lead to cost and effort reduction  The path of movements can be better visualized  Measures the distances moved and points out if the work stations are suitably located

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Method Study - Procedure  Examine – asking questions 

Purpose – what is done ?



Person – Who does it ?



Place – Where it is done ?



Means – how is it done ?



Sequence – When it is done 1. Why is it necessary ,why is it done by that method etc., 2. Determine alternate ways of doing 3. Determine best method of of doing

Operation Analysis 10

Method Study - Operation Analysis 

Detailed study of different operations involved In doing a work



Some of the work elements to be







Combined



Eliminated



Altered in sequence

Operation analysis involves in optimizing the processes with regard to: 

Worker in terms of fatigue



Setup in terms of modification of setup, availability of equipments and number of setups



Material specification,cost



Material handling – backtracking,distance reduction

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Operations



Tools and fixtures – easy to use



Work condition – lighting,ventilation

Analysis of motion : 

Identification of productive and idle motions



Elimination of unnecessary and non- productive motions

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Redesign of the existing operatios by employing minimum number of motions and appropriate sequence

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Method Study - Work place Layout design 

Materials and tools to be available in predetermined places closes to the worler



To be located in the order of their use



Use of gravity , for raw material to reach operator wherever possible



Comfortable posture for operator



Should be able to operate levers and handles without alteration in body postures



Working place classification 

Actual working area – most convenient area to work (1)



Normal working area – it is within the reach of the operator (2)



Maximum Working area - It is accessible with full arms stretch (3) 3 1

2

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Method Study - Procedure  Develop best method which is : 

Practical , feasible, safe and economical



Acceptable to design and production and quality control and sales

 Install developed method and examine for problems  Maintain new method by periodic checks and verifications

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Work Measurement Work measurement is the application of techniques designed to establish The time for a qualified worker to Carry out a specified job at a defined level of performance A qualified worker is one who is: Accepted as having the necessary physical attributes, Who possesses the required intelligence and education, Who has acquired the necessary skill and knowledge to carry out the work in hand to Satisfactory standards of safety,quantity and quality

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Work Measurement - Application The uses of work measurement • To compare the efficiency of alternative methods • To balance the work of members of teams, in association with Multiple activity chart • To determine, in association with man machine multiple activity charts, the number of machines an operative can run • The time standards, once set, may then be used: – For production planning and scheduling – Determine plant and Labour requirements – To set standards of machine utilisation and Labour performance and as a basis for incentive schemes – To provide information for Labour-cost control 15

Work Measurement Technique – Time Study Time study is a work measurement technique for recording the times and rates of working for:  The elements of a specified job Carried out under specified conditions, Analysing the data so as to obtain the time necessary for carrying out the job at a defined level of performance Basic time study equipment

A stop watch A study board time study forms camera

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Time Study – Procedure Obtaining and recording all the information available about the job, the operative and the surrounding conditions Recording a complete description of the method,breaking down the operation into elements An element is a distinct part of a specified job selected for convenience of observation, measurement and analysis A work cycle is the sequence of elements which are required to perform a job or yield a unit of production.The sequence may sometimes include occasional elements  Measuring with a timing device(usually a stopwatch) and recording the time taken for each element  At same time, assessing the effective speed of working(Rating)  Extending the observed times to Basic times  Determining the allowances to be made over and above the basic time for the operation  Determining the standard time for the operation

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Time Study – Rating & Rating Factor Rating • Rating is the assessment of the worker’s rate of working relative to the observer’s concept of the rate corresponding to standard performance How the rating factor is used • Observed Time x Rating = Basic time Standard Rating(100) • Basic time is the time for carrying out an element of work at standard rating 18

Time Study – Standard Time

+ CA

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Work Measurement – Other Techniques Predetermined Motion Time System (PMTS): 

Does not measure elemnt time



All manual tasks are made up of certain basic human movement which are common to all jobs



The average time taken to perform a movement is constant (BS 3138 :1969)

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Basic time can be calculated by summing times of all motions and applying rating factor

Method Time Measurement (MTM): 

Time measurement unit ( 1 TMU = 0.0006 min.)

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Analyses the human movements , depending on types of motion and conditions predetermined time values are given for each motion

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Basic time can be calculated by summing times of all motions and applying rating factor

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