Studying And Calibrating The Software Cost Estimation Model COCOMO

Software cost estimation model COCOMO has great impact on the field of project metrics. Above all, this paper introduces some knowledge about software cost estimation and its some models and technologies, then emphatically discusses the Basic model of C0C0M081, the Application Composition model and the Early Design model and the Post-Architecture model of COCOMO Ⅱ. This paper also points out how to use COCOMO model to estimate software costs. In order to improve the accuracy of COCOMO in the process of project metrics, this paper will calibrate some parameters in these models according to software developing environment. So COCOMO will yield more accurate effort predictions. We use the generalized g-prior calibration approach for the Early Design model and Post-Architecture model ,the Wideband Delphi technology for the Application Composition mode and the Relevant Algorithms of Logarithm Data for the Basic model to yield better estimates. Finally, we have developed COCOMO system to estimate software costs and to calibrate parameters and to manager project database.