【正文】 d below. Use this data to estimate the shop’s learning rate in manufacturing the turbines. Unit No. LaborHours Unit No. LaborHours 1 140 5 95 2 118 10 81 3 109 15 75 4 102 20 68 50 Example: EZ Machine Shop (A) Learning Curve Arithmetic Analysis Compute the learning rate for each of the “doubles”. Units 1 and 2 118/140 = .8429 Units 2 and 4 102/118 = .8644 Units 5 and 10 81/95 = .8526 Units 10 and 20 68/81 = .8395 (.8429 + .8644 + .8526 + .8395)/4 = .8499 The approximate learning rate is 85%. 51 Learning Curves LearningCurve Tables A table of learning curve coefficients (Table ) allows us to pute: ? The laborhours for the nth unit in a production run ? The total laborhours for the entire production run, where the nth unit is the last unit in the run 52 Example: EZ Machine Shop (B) LearningCurve Tables The manager of EZ Machine Shop wants a good estimate of the total laborhours required to manufacture the entire 100 turbines. Also, he is curious about how many laborhours will be needed for the last (100th) unit. Use the observed 85% learning rate and 140 laborhours required for the first turbine to pute your estimates. 53 Example: EZ Machine Shop (B) LearningCurve Tables Total LaborHours Required for 100 Units = (Hours for 1st unit)(Table total time: 85%, 100th unit) In Table , locate the line for the 100th unit and read across to the Total Time column under the 85% learning rate. The value is . Total LaborHours Required for 100 Units = 140() = 6,125 laborhours 54 Example: EZ Machine Shop (B) LearningCurve Tables Labor Hours Required for the 100th Unit = (Hours for 1st unit)(Table unit time: 85%, 100th unit) In Table , locate the line for the 100th unit and read across to the Unit Time column under the 85% learning rate. The value is .340. = 140(.340) = laborhours (100th unit will require 34% of the time 1st unit required) 55 Learning Curves Logarithmic Analysis The following relationship allows us to pute Tn, the laborhours required to produce the nth unit: Tn = T1(nb) and b = log r/log 2 where: T1 = laborhours to produce the first unit b = slope of the learning curve r = learning rate percentage 56 Example: EZ Machine Shop (C) Logarithmic Analysis Compute, using logarithmic analysis, the laborhours required for the 50th turbine (assuming an 85% learning rate and 140 laborhours required for the 1st unit). b = log (.85)/log (2) = T50 = 140() = .399623 or .400 (Our result agrees with the value in Table ) 57 Learning Curves ? Selecting a learning rate ? Industry journals ? Historical experience ? Uses and limitations ? Products and services tend to be custom designed ? Batches tend to be small ? Product/services tend to be plex.... learning occurs quickly 58 Employee Health amp。 ? OSHA safety and health in the workplace. Federal... proactive ? Worker’s Compensation safety and health in the workplace. State .... reactive ? EPA Environmental protection outside of the workplace. Federal... proactive ? Safety and Health departments in plant 59 WrapUp: WorldClass Practice ? World class panies recognize employees are of strategic and tactical importance ? Workers must have problemsolving abilities and be trained, crosstrained, educated and empowered so that they can work in teams and respond to customer needs ? Organizational structure must be developed to encourage full use of employees ? Information is the main media of management 60 End of Chapter 1