1478. A Critical Look at the Development and Apllication of Airframe Cost Models

Paper

Abstract

This paper critically examines the state of the art of airframe production cost estimating models. The main idea expressed is that models often fail to achieve their objectives because developers limit themselves to using inadequate empirical data and quantitative methods. Also, users accept models as rigid and rarely feel comfortable in changing the values of independent variables, cost factors, and coefficients t o conform with their experience or expectations.
Some of the points raised concerning the development and application of airframe cost estimating models include the following:
– Developers should provide information which will enable users to accept, reject, or modify the model in accordance with their requirements- Users should assure that cost models are appropriate for the purpose for which they are applied by carefully reviewing critical assumptions contained in them and the data upon which they are based.
– Cost models based exclusively on empirical data are inadequate for estimating costs of advanced technologies.
– Rules of thumb and general information may augment empirical data when applied judiciously.
– Actual experience within a given firm and among similar firms varies widely. Therefore, ranges of factors and variables must be considered and applied in developing and using cost models.