An Empirical Study of the Efficacy of COCOMO II Cost Drivers in Predicting a Project’s Elaboration Profile

A project’s elaboration profile consists of a set of ratios called elaboration factors that quantify the step-wise expansion of a project’s requirements from very high-level business objectives to very low-level source lines of code. Knowledge of a project’s elaboration profile can be extremely useful in deriving an early estimate of its size. The real challenge, however, is to predict the elaboration profile. Can the COCOMO II cost drivers be used for this purpose? This paper attempts to answer this question. It examines the elaboration profiles and COCOMO II cost driver ratings of 25 small real-client projects. The data collection process is thoroughly described and the cost drivers relevant at each stage of elaboration are identified. Relationships between elaboration factors and relevant cost drivers are analyzed using simple as well as multiple regression. The results indicate that there is no magical formula for predicting the various elaboration factors just from the values of COCOMO II cost drivers. This may be due to some confounding factors which are highlighted in this paper.