Tag Archives: S-Curve

Acquisition Challenge: The Importance of Incompressibility in Comparing Learning Curve Models


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Authors: Capt Justin R. Moore, USAF, John J. Elshaw, Adedeji B. Badiru, and Lt Col Jonathan D. Ritschel, USAF

The Department of Defense (DoD) cost estimating methodology currently employs T. P. Wright’s 75-plus-year-old learning curve formula. The goal of this research was to examine alternative learning curve models and determine if a more reliable and valid cost estimation method exists, which could be incorporated within the DoD acquisition environment. This study tested three alternative learning models (the Stanford-B model, DeJong’s learning formula, and the S-Curve model) to compare predicted against actual costs for the F-15 A-E jet fighter platform. The results indicate that the S-Curve and DeJong models offer improvement over current estimation techniques, but more importantly—and unexpectedly—highlight the importance of incompressibility (the amount of a process that is automated) in learning curve estimating.

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