Impact of CMMI Based Software Process Maturity on COCOMO II’s Effort Estimation

Majed Al Yahya, Rodina Ahmad, and Sai Lee
Department of Software Engineering, University of Malaya, Malaysia

Abstract: The software capability maturity model has become a popular model for enhancing software development processes with the goal of developing high-quality software within budget and schedule. The software cost estimation model, constructive cost model, in its last update (constructive cost model II) has a set of seventeen cost drivers and a set of five scale factors. Process maturity is one of the five scale factors and its ratings are based on software capability maturity model. This paper examines the effect of process maturity on software development effort by deriving a new set of constructive cost model II’s PMAT rating values based on the most recent version of CMM, i.e., capability maturity model integration. The precise data for the analysis was collected from the record of 40 historical projects which spanned the range of capability maturity model integration levels, from level 1 (lower half and upper half) to level 4, where eight data points were collected from each level. We followed the ideal scale factor method in order to withhold the effect of the constructive cost model II’s PMAT scale factor. All prediction accuracies were measured using PRED. The study showed that the proposed model (with the new PMAT rating values) yielded better estimates as compared to the generic , constructive cost model II model’s estimates.

Received November 8, 2008; accepted December 15, 2008