Heizer mod e
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This document discusses learning curves in operations management. It contains 3 learning objectives: 1) define a learning curve, 2) use arithmetic concepts to estimate times, and 3) compute learning curve effects using logarithmic and learning coefficient approaches. It then provides an outline of topics, examples of industries with learning curves, and explanations of the arithmetic, logarithmic, and learning coefficient approaches for estimating costs and times with experience.
Heizer mod e
- 1. Operations Management Module E – Learning Curves PowerPoint presentation to accompany Heizer/Render Principles of Operations Management, 7e Operations Management, 9e © 2008 Prentice Hall, Inc. E–1
- 2. Outline Learning Curves in Services and Manufacturing Applying the Learning Curve Arithmetic Approach Logarithmic Approach Learning-Curve Coefficient Approach Strategic Implications of Learning Curves Limitations of Learning Curves © 2008 Prentice Hall, Inc. E–2
- 3. Learning Objectives When you complete this module you should be able to: 1. Define a learning curve 2. Use the arithmetic concept to estimate times 3. Compute learning curve effects with the logarithmic and learning-curve coefficient approaches 4. Describe the strategic implications of learning curves © 2008 Prentice Hall, Inc. E–3
- 4. Learning Curves Based on the premise that people and organizations become better at their tasks as the tasks are repeated Time to produce a unit decreases as more units are produced Learning curves typically follow a negative exponential distribution The rate of improvement decreases over time © 2008 Prentice Hall, Inc. E–4
- 5. Learning Curve Effect Cost/time per repetition 0 Number of repetitions (volume) Figure E.1 © 2008 Prentice Hall, Inc. E–5
- 6. Learning Curves T x Ln = Time required for the nth unit T = unit cost or unit time of the first unit L = learning curve rate n = number of times T is doubled First unit takes 10 labor-hours 70% learning curve is present Fourth unit will require doubling twice — 1 to 2 to 4 Hours required for unit 4 = 10 x (.7)2 = 4.9 hours © 2008 Prentice Hall, Inc. E–6
- 7. Learning Curve Examples Learning- Curve Improving Cumulative Slope Example Parameters Parameter (%) Model -T Ford Price Units produced 86 production Aircraft Direct labor-hours Units produced 80 assembly per unit Equipment Average time to Number of 76 maintenance replace a group of replacements at GE parts Steel Production worker Units produced 79 production labor-hours per unit produced Table E.1 © 2008 Prentice Hall, Inc. E–7
- 8. Learning Curve Examples Learning- Curve Improving Cumulative Slope Example Parameters Parameter (%) Integrated Average price per Units 72 circuits unit produced Handheld Average factory Units 74 calculator selling price produced Disk memory Average price per Number of bits 76 drives bit Heart 1-year death rates Transplants 79 transplants completed Table E.1 © 2008 Prentice Hall, Inc. E–8
- 9. Uses of Learning Curves Internal: labor forecasting, scheduling, establishing costs and budgets External: supply chain negotiations Strategic: evaluation of company and industry performance, including costs and pricing © 2008 Prentice Hall, Inc. E–9
- 10. Arithmetic Approach Simplest approach Labor cost declines at a constant rate, the learning rate, as production doubles Nth Unit Produced Hours for Nth Unit 1 100.0 2 80.0 = (.8 x 100) 4 64.0 = (.8 x 80) 8 51.2 = (.8 x 64) 16 41.0 = (.8 x 51.2) © 2008 Prentice Hall, Inc. E – 10
- 11. Logarithmic Approach Determine labor for any unit, TN , by TN = T1(Nb) where TN = time for the Nth unit T1 = hours to produce the first unit b = (log of the learning rate)/ (log 2) = slope of the learning curve © 2008 Prentice Hall, Inc. E – 11
- 12. Logarithmic Approach Determine labor for any unit, TN , by TN = T1(Nb) Learning b where TN = time for the Nth unit Rate (%) T1 = hours to70 produce the – .515 first unit 75 – .415 b = (log of the learning rate)/(log 2) 80 – .322 = slope of 85 learning.234 the – curve 90 – .152 Table E.2 © 2008 Prentice Hall, Inc. E – 12
- 13. Logarithmic Example Learning rate = 80% First unit took 100 hours TN = T1(Nb) T3 = (100 hours)(3b) = (100)(3log .8/log 2) = (100)(3–.322) = 70.2 labor hours © 2008 Prentice Hall, Inc. E – 13
- 14. Coefficient Approach TN = T1C where TN = number of labor- hours required to produce the Nth unit T1 = number of labor- hours required to produce the first unit C = learning-curve coefficient found in Table E.3 © 2008 Prentice Hall, Inc. E – 14
- 15. Learning-Curve Coefficients Table E.3 70% 85% Unit Number (N) Unit Time Total Time Unit Time Total Time 1 1.000 1.000 1.000 1.000 2 .700 1.700 .850 1.850 3 .568 2.268 .773 2.623 4 .490 2.758 .723 3.345 5 .437 3.195 .686 4.031 10 .306 4.932 .583 7.116 15 .248 6.274 .530 9.861 20 .214 7.407 .495 12.402 © 2008 Prentice Hall, Inc. E – 15
- 16. Coefficient Example First boat required 125,000 hours Labor cost = $40/hour Learning factor = 85% TN = T1C T4 = (125,000 hours)(.723) = 90,375 hours for the 4th boat 90,375 hours x $40/hour = $3,615,000 TN = T1C T4 = (125,000 hours)(3.345) = 418,125 hours for all four boats © 2008 Prentice Hall, Inc. E – 16
- 17. Coefficient Example Third boat required 100,000 hours Learning factor = 85% New estimate for the first boat 100,000 = 129,366 hours .773 © 2008 Prentice Hall, Inc. E – 17
- 18. Strategic Implications To pursue a strategy of a steeper curve than the rest of the industry, a firm can: 1. Follow an aggressive pricing policy 2. Focus on continuing cost reduction and productivity improvement 3. Build on shared experience 4. Keep capacity ahead of demand © 2008 Prentice Hall, Inc. E – 18
- 19. Industry and Company Learning Curves In C du om st ry Price per unit (log scale) pa pr ny ice co st (c) Loss (b ) Gross profit (a) margin Figure E.2 Accumulated volume (log scale) © 2008 Prentice Hall, Inc. E – 19
- 20. Limitations of Learning Curves Learning curves differ from company to company as well as industry to industry so estimates should be developed for each organization Learning curves are often based on time estimates which must be accurate and should be reevaluated when appropriate © 2008 Prentice Hall, Inc. E – 20
- 21. Limitations of Learning Curves Any changes in personnel, design, or procedure can be expected to alter the learning curve Learning curves do not always apply to indirect labor or material The culture of the workplace, resource availability, and changes in the process may alter the learning curve © 2008 Prentice Hall, Inc. E – 21
Editor's Notes
- #5: This slide provides some reasons that capacity is an issue. The following slides guide a discussion of capacity.
- #6: This slide provides some reasons that capacity is an issue. The following slides guide a discussion of capacity.
- #7: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #8: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #9: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #10: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #11: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #12: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #13: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #14: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #15: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #16: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #17: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #18: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #19: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #20: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #21: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.
- #22: This slide can be used to frame a discussion of capacity. Points to be made might include: - capacity definition and measurement is necessary if we are to develop a production schedule - while a process may have “maximum” capacity, many factors prevent us from achieving that capacity on a continuous basis. Students should be asked to suggest factors which might prevent one from achieving maximum capacity.