The concept of the learning curve was introduced to the aircraft industry in 1936 by T. P. Wright, who described a basic theory for obtaining cost estimates based on repetitive production of airplane assemblies. He stated that there is a relationship between the Average Variable Cost ( AVC) and Cumulative Lifetime Production ( n).

Learning Curves (or Experience Curves) have been applied to all types of work, from simple tasks to complex ones, such as spacecraft manufacturing. The theory of learning recognizes that repetition of the same operation results in progressively less time or effort expended on that operation. The Wright Learning Curve is based on the assumption that the direct labor man-hours necessary to complete a unit of production will decrease by a constant percentage each time the production quantity is doubled.

The slope of the learning curve is 100 minus the rate of learning. If the rate of improvement is 10% between doubled quantities, then the learning percent would be 90% (100 - 10 = 90). The learning curve can emphasize both time and cost. Effort can be expressed in terms of cost, man-hours, or any other measure of effort. Learning curve values will be between 50% (0.5) and 100% (1.0). Only recurring costs are impacted by "learning" and will affect the learning curve slope.

Figure 8.1: Typical learning curve slopes

Current learning curve theory is based on the following conclusions:

• The rate of improvement is consistent enough to be used as a...