Operations management by stevenson 9th ch7s

7S

Learning Curves

McGraw-Hill/Irwin

Copyright © 2007 by The McGraw-Hill Companies, Inc. All


Learning Objectives
 Explain the concept of learning curves
 Make time estimates based on learning
curves
 List and briefly describe some of the main
applications of learning curves
 Outline some of the cautions and criticisms
of learning curves
 Estimate learning rates from data on job
times
7S-2


Learning Curves
 Learning curves: the time required to
perform a task decreases with
increasing repetitions

7S-3


Learning Effect

Time per repetition

Figure 7S.1

Number of repetitions

7S-4


Learning with Improvements

Time per unit

Figure 7S.2

Average

Improvements may create a
scallop effect in the curve.

Time

7S-5


Applications of Learning Curves
1.Manpower planning and scheduling
2.Negotiated purchasing
3.Pricing new products
4.Budgeting, purchasing, and inventory

planning
5.Capacity Planning

7S-6


Worker Learning Curves

Time/cycles

Figure 7S.4

A (underqualified)
B (average)
Standard time
C (overqualified)
One week

Training time

7S-7


Cautions and Criticisms
 Learning rates may differ from
organization to organization
 Projections based on learning curves
should be viewed as approximations
 Estimates based the first unit should
be checked for valid times

 At some point the curve might level off
or even tip upward
7S-8


Cautions and Criticisms
 Some improvements may be more
apparent than real
 For the most part, the concept does not
apply to mass production
 Learning curves sometimes fail to
include carryover effects
 Life cycles, flex manufacturing can
affect application of learning curves

7S-9