Calibrating Software Cost Models Using Bayesian Analysis

Abstract

The COCOMO II research effort started in 1994 with the aim of updating software cost estimation models, such as the 1981 COnstructive COst MOdel and its 1987 Ada update. Both the earlier models experienced difficulties in estimating software projects of the 90s due to challenges such as non-sequential and rapiddevelopment process models; reuse-driven approaches involving commercial-off-the-shelf (COTS) packages, reengineering, applications composition, and application generation capabilities; object-oriented approaches supported by distributed middleware; software process maturity effects and process-driven quality estimation. The COCOMO II research effort aims at alleviating these problems and is concentrated on developing a model well-suited for the 1990s and then annually updating it for the forthcoming years. The initial definition of the COCOMO II model and its rationale are described in [Boehm95]. The model uses Source Lines of Code and/or Function Points for the sizing parameter...