1. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-1 Operations Management Work Measurement Supplement 10

2. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-2 Outline  LABOR STANDARDS AND WORK MEASUREMENT  HISTORICAL EXPERIENCE  TIME-STUDIES  PREDETERMINED TIME STANDARDS  WORK SAMPLING

3. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-3 Learning Objectives When you complete this supplement, you should be able to : Identify or Define :  Four ways of establishing labor standards Describe or Explain :  Requirements for good labor standards  Time study  Predetermined time standards  Work sampling

4. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-4  Costing labor content of products  Planning staffing needs  Estimating time and cost for bids  Planning production (crew size and work balance)  Estimating expected production  Basing wage-incentive plans  Determining employee efficiency Uses of Labor Standards

5. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-5  Historical experience  Time studies  Predetermined time standards (MTM)  Work sampling © 1995 Corel Corp. Sources of Labor Standards

6. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-6 Historical Experience  Relatively easy, convenient, and inexpensive  Not objective, unknown accuracy Not recommended

7. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-7  Labor standards are based on observing worker doing task  Observe only a sample of work  Use average time & pace to set standard  Disadvantages  Requires a trained & experienced analyst  Standard cannot be set before task is performed Time Studies

8. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-8 The Eight Steps to Conducting a Time Study ÊDefine the task to be studied (after a methods analysis) ËBreak down the task into precise elements ÌDecide how many times each element of the task must be measured ÍRecord the times and ratings of performance for the task elements  Compute the average observed cycle time (element times adjusted for unusual influences)

9. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-9 6.Compute the normal time for each task element: Normal time = (Average actual cycle time) x (Rating factor) 7.Sum the normal times for each element to develop a total normal time for the task 8.Compute the standard time: The Eight Steps to Conducting a Time Study - continued Standard time = Total normal time 1- Allowance factor

10. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-10 Allowances  Personal time allowance - 4% - 7% of total time - use of restroom, water fountain, etc.  Delay allowance - based upon actual delays that occur  Fatigue allowance - to compensate for physical or mental strain, noise level, tediousness, heat and humidity, assumption of an abnormal position, etc.

11. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-11 Rest Allowances (%) for Various Classes of Work 1. Constant allowance (a) Personal allowance ……………... (b) Basic fatigue allowance ………… 2.Variable allowances: (A) Standing allowance …………….. (B) Abnormal position (I) Awkward (bending) …………. (ii) Very awkward (lying, stretching) …………………….. (C) Use of force or muscular energy in lifting, pulling, pushing Weight lifted (pounds) 20 ………………………………… 40…………………………………. 60…………………………………. 5 4 2 7 3 9 17

12. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-12 Rest Allowances (%) for Various Classes of Work - Continue (D) Bad light ( i) Well below recommended ….. (ii) Quite inadequate ……………. (E) Atmospheric conditions (heat and humidity) Variable ………………………….. (F) Close attention (i) Fine or exacting ……………… (ii)Very fine or very exacting …... (G) Noise level (i) Intermittent – loud …………… (ii) Intermittent – very loud or high-pitched 2 5 1-10 2 5 2 5

13. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-13 Rest Allowances (%) for Various Classes of Work - Continue (H) Mental strain (i) Complex or wide span of attention ……………………… (ii) Very complex ……………. (I) Tediousness (i) Tedious ……………………. (ii) Very tedious ……………… 4 2 5

14. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-14 Time Studies - Sample Size h = accuracy level desired as percent of job element, expressed as a decimal (5% = 0.05) z = number of standard deviations required for the desired level of confidence s = standard deviation of the initial sample x = mean of the initial sample

15. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-15 Considerations in Determining Sample Size ¶ How accurate do you want to be? · What level of confidence do you want your measurements to have? ¸ How much variation exists within the job elements?

16. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-16 Common z values

17. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-17 Allowance factor Nonwork time Total time Average element time  Element times Number of cycles Normal timeAverage element time * Perf. Rating Standard time Total normal time 1 - Allowance factor = = = = Time Study Equations

18. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-18  Labor standards are set from times in published tables (e.g., MTM Table)  Procedure  Divide manual work into basic elements  Look up basic element times in table; sum  Advantages  Times established in laboratory setting  Useful for planning tasks  Widely accepted by unions Predetermined Time Standards

19. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-19 Time TMU Hand in Motion Distance Moved (in) ABCAB 3/4 or less 2.0 1.6 1 2.5 3.62.3 2 4.0 5.93.52.7 A Reach to object in fixed location. B Reach to object in variable locations. C Reach to object jumbled with others. 1 TMU =.0006 minutes MTM Table for Reach Motion

20. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-20 Sample MTM Table for GET and PLACE Motions

21. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-21 MTM-HC Analysis: Pouring Tube Specimen Element DescriptionElementTime Get tube from rackAA235 Get stopper, place on counter AA235 Get centrifuge tube, place at sample tube AD245 Pour (3 sec.)PT83 Place tubes in rack (simo)PC240 0.0006*238=Total standard minutes = 0.14 Total TMU 238

22. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-22  Labor standard is set using output and % of time worker spends on tasks  Involves observing worker at random times over a long period  Advantages  Less expensive than time studies  Observer requires little training  Disadvantages  Ineffective with short cycles Work Sampling

23. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-23  Used for  Ratio delay studies  Setting labor standards  Measuring worker performance Work Sampling

24. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-24 The Five Step Work Sampling Procedure 1.Take a preliminary sample to obtain an estimate of the parameter value 2.Compute the sample size required 3.Prepare a schedule for observing the worker at appropriate times 4.Observe and record worker activities; rate worker performance 5.Determine how workers spend their time (usually as a percent)

25. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-25 Work Sampling - Sample Size p = estimated value of sample proportion (of time worker is observed busy or idle) h = accuracy level desired in percent, expressed as a decimal

26. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-26 Normal Time = (Total Time) (% of time working) (Rating) Number of units Produced Standard Time = Normal Time 1 - Allowance Work Sampling Equations

27. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 S10-27 Work Sampling Time Studies