PTTQM (BU-3)Module 2MODULE 2 and MODULE 3

1. What is work-study? Discuss the concepts of method study and work measurement as components of work study.Work study is concerned with the analysis of work methods and the equipment used in performing the job, the design of optimum work method and the standardization of proposed work methods.Work study covers: Method study Work Measurement

Method studyMethod study is a technique of observing, recording and examining the present method of performing the work with a view to develop a cheaper and productive method. It covers work processes, working conditions, equipments and tools used to carry out the job.

Advantages of Method study:1. Work simplification2. Improved method( cheaper and productive03. Better quality product4. Improved layout5. Better material handling6. Better work flow7. Less fatigue to operator8. Shorter production time9. Job satisfaction

Work MeasurementWork measurement is concerned with techniques to establish work content of specified task by measuring the time required to carry out the job at defined standard of performance by a qualified worker and a qualified worker is one who has the necessary physical attributes, intelligence, education and skills and knowledge to carry out the work to satisfactory standards of safety, quality and quantity.Objectives of Work Measurement Improved planning and control Basis for sound incentive schemes Better utilization of manpower Better labour productivity Better labour cost control

2. What is method study (Methods analysis)? Briefly explain the procedure of method study.Method study is a technique of observing, recording and examining the present method of performing the work with a view to develop a cheaper and productive method. It covers work processes, working conditions, equipments and tools used to carry out the job.

Method study procedurei. Selection of work based on present problems and scope for improvementii. Record relevant facts and information on existing method , use appropriate charts and diagramsiii. Examining recorded facts ( use what, when , how, who, where, why type of questioning on collected facts)iv. Developing improved method by a. Eliminating wasteful tasksb. Simplifying tasksc. Combining tasksd. Evaluating alternatives with respect to cost, savings, feasibility, reaction of employees, short term and long term implications etc.v. Installing improved method ( plan, schedule, coordinate, involve all concerned)vi. Maintaining the new method ( feedback on performance towards objectives)

9. Distinguish between operations process chart and flow process chart.Operations and Flow process charts are the recording techniques used in method study procedure. Operation process chart- gives the sequence of operations, machine to be used, tooling needed, inspection stages. These are also called ROUTING SHEETS. Using these charts all the operations and inspections are recorded.Flow process charts-gives graphically, with symbols, manufacturing operations, inspection stages, Transport operations, Delays, storage requirements. There are three types of flow process charts. They are (a) Man type - All the activities of man are recorded(b) Material type - All the activities of the material are recorded (c) Equipment type - All the activities of equipment or machine are recorded.

10. Write the different types of recording in Method study.Different recording techniques in method study are:#Chart type Usage

1Outline process chartCovers only main operations and Inspections

2Operations process chartIncludes operations, inspections and material inputs

3Flow process charts Includes sequence of operations, transportation, inspections, delays and storages. For Material or product For Man For Machine

4Two handed process chartsDepicts the activities of both hands or limbs

5

Multiple activity chartFor more than one worker/ machine or equipment

6

Man- machine chart Worker and machine on common time scale Worker and two machines on common time scale

7Flow diagramActual paths followed by materials. Diagram drawn to scale

8

String diagramSting used to trace the path of materials or workmen in a scale plan or a Model. To measure distances traveled.

9

SIMO chartSimultaneous motion cycle chart. Used for very small cycle time operations.

11. Explain the concept of work measurement and what are the various types of work measurement available?

Work Measurement is a Work study technique of measuring the Work Content of a job. It usually succeeds method study and/or method establishment. Two main Work measurement techniques are time study and Work Sampling, apart from the approach of time synthesis.

Time Study : A Work measurement technique for recording the times and rates of working for elements of a specified job under specified conditions and for analysing the data to determine the time necessary to carry out the job at a defined level of performance.Time Study Procedure: Theory of Standard Time: Start by selecting an operator with a known Rating, and observe his performance over a number of cycles. Step 1 : Record the observed time(s) Step 2 : Determine the Central tendency, Usually the Mean, or, for a large number of observations, the Mode. Step 3 : Multiply the Average Observed Time with Operator Rating. This gives the Normal Time. Step 4 : Add on the approved allowances (Personal and non-personal) to the Normal Time. This gives the STANDARD TIME, which the basis of the final agreement of productivity between Management and Unions.

Work Sampling: A non-time measuring Work measurement technique for recording the proportion of productive instants in one operation cycle. This may then be interpolated into determining the standard times. Advantages Economical Not necessary to use trained work study experts No stop watch measurementsLimitations Little value to improve the operations If random sampling is not done results will be erroneous

12. What is the difference between observed time, normal time and standard time?The observed time is simply the average of the recorded times. Thus, OT = xi / n

The normal time is the observation time adjusted for worker performance. It is computed by multiplying the observed time by a performance rating. That is, NT = OT x PR

The standard time is the amount of time it should take a qualified worker to complete a specified task, working at a sustainable rate, using given methods, tools, equipments, raw materials and workplace arrangement. The standard time is ST = NT x AFWhere NT Normal Time, AF Allowance factor13. What is process mapping? Explain.Process mapping is a method to graphically describe the steps that make up a process. It consists of a set of tools that enable us to systematically document, analyze, improve, and redesign a process. It is the first step of process management.

14. Mention the benefits of process mapping.The benefits of process mapping are as follows: Ability to visually understand and document a process Ability to take a holistic view of process objectives Develop true buy-in from employees Develop a sense of pride among employees Create customer-focused processes

15. Explain the major steps in process mapping.The following are the steps in process mapping:1. Process Identification2. Information gathering3. Interviewing and map generation4. Map Analysis

Step 1: Process identification Identification of trigger events, i.e., actions from customers that cause the start of a process Name the process for each of the trigger events generated by the customers

Step 2: Information gathering Description of a process Identification of process owners Discussion with process owners Business and process objectives Business and process risks Key controls Measures of success

Step 3: Interviewing and map generation Secure buy-in Select the right people for interviews Set up the interviews setting, time, etc. Active listening and recording Use drill-down approach (unit, task and action levels) Review and revise

Step 4: Map analysis elimination of wastes Delays Duplication Approvals Hand-offs Errors Uncertainties

Important Formulae on Work Study1.a) Observed Time per unit :OT = xi / n1. b) Observed Time for n Units:OT = Working time Idle timeWherexi Recorded time of an observation,n No. of Observations

2. Normal time (Basic Time):NT = OT x PRWhere OT Observed time,PR Performance Rating (Rating Factor)3. Standard Time:ST = NT + AFWhere NT Normal Time, AF Allowance factor

4. No. of observations in Work Sampling n= pqz2 / a2Where p = percentage of observations where machine was idle q = 1- p (percentage machine not idle) z = desired confidence level (z=1 for 68.3%, 2 for 95.4%, 3 for 99%) a = desired accuracy or error (in percentage)

Exercise Problems:1. Calculate the standard time per unit which has a shift of 8 hours duration, with the following data. Observed time per unit = 5 minutes, Rating factor = 120%, Total allowances = 33.5 % of normal time.

2. The following information is available from a work-sampling study carried out over 48-hours work per week:Total units produced = 300 Average performance rating = 90% Idle time = 18% total allowances = 20% of basic time Determine the standard time per unit.

3. A manufacturing company works 8 hrs shift a day and produces 320 units of a product. The idle time is 15%. Assuming 10% of normal time (NT) for relaxation allowance, calculate the standard time (ST) per piece. Performance Rating is 120%.

4. A time study on a job relates to the following:Hrs worked: 8 HrsAverage performance rating: 90%Total allowances for 8 hrs: 55 minutesUnits produced: 400Idle time: 10%Find the standard time per piece.

5. The Time for making 4 pieces of an item with elements a, b, c, d is as follows. Fatigue allowance is 25% of normal time. Find the standard time per piece.ElementCycle 1( min)Cycle 2( min)Cycle 3( min)Cycle 4( min)Rating

a1.21.31.31.485

b0.70.60.650.75120

c1.41.31.31.290

d0.50.50.60.470

6. An industrial engineer, deputed to conduct a time study for a job, has, after observation, divided the job into 5 elements. He had noted the timings for four cycles of the job as below:ElementTime in minutesPerformance rating

Cycle 1Cycle 2Cycle 3Cycle 4(%ge)

11.2461.3281.2981.30690

20.9720.8950.7980.919100

30.9141.8751.9641.972100

42.1212.1982.1462.421110

51.2531.1751.4132.218100

(i)Are there any outliers in the data i.e., probable errors in reading or recording data which should not be included in the analysis?(ii) Compute the basic time for the job and the standard time if a relaxation allowance of 12%, a contingency allowance of 3% and an incentive of 20% are applicable for the job.

University examination Problems on Standard time calculation7) 15 people working 8 hours a day were able to produce 4000 numbers of an item. People who have produced the above quantities were estimated to be working at 120% performance rating. The company allows 10% as allowances on normal time. Find the standard time per item.

8) A job takes 3 minutes and the operator was found to be working @ 120% speed. The company has a policy of giving 10% allowances on normal time. The company wants 500 components per day. The company now works in two shifts with effective working hours of 15 hours (i.e. 8 hrs hr lunch x 2). Calculate the no. of operators required per day to meet the requirement.

Prof. Raghavendra, KSM, BangalorePage | 5