The Learning Curve

The Learning Curve

Introduction

The concept of the learning curve was introduced to the aircraft industry in 1936 by T. P. Wright. Wright described a basic theory for obtaining cost estimates based on repetitive production of airplane assemblies. Since then, learning curves (also known as progress functions) have been applied to all types of work from simple tasks to complex jobs like manufacturing.

The theory of learning recognizes that repetition of the same operation results in less time or effort expended on that operation. While the learning curve emphasizes time, it can be easily extended to cost as well.

Typical Learning Curve

The following figure is of a fairly typical of a learning curve. It depicts the fact that the learning curve does not proceed smoothly: the plateaus and troughs are normal features of the process.

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Figure 1. A Typical Learning Curve

Basic Concept

The concept of a Learning Curve is motivated by the observation that, each time the cumulative production doubles, the hours required to produce the most recent unit decreases by approximately the same percentage. The constant percentage by which the costs of doubled quantities decrease is called the rate of learning. The slope of the learning curve is 100 minus the rate of learning.

For example, if the hours between doubled quantities are reduced by 20% (rate of learning), it would be described as a curve with an 80% slope.  Below is a picture of what that curve might look like:

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Figure 2. An 80% Learning Curve

For an 80% learning curve,

▪ If cumulative production doubles from 50 to 100, then the hours required to produce the 100-th unit is 80% of that for the 50-th unit.

▪ If cumulative production doubles from 100 to 200, then the hours required to produce the 200-th unit is 80% of that for the 100-th unit.

Types of learning curve

a) Steep learning curve- A steep learning curve is often referred to indicate that something is...