Automated Support for Software Cost Estimation Using Web-CoBRA

Software cost estimation is a crucial yet very difficult task for a project manager at the very beginning of a new project. Since software projects are always different in nature, past projects may not necessarily cover all aspects of a new project when used as a basis for cost estimation. The CoBRA hybrid cost estimation technique uses expert knowledge to build a causal model of context-specific cost factors and past project data to predict costs in terms of effort as well as to assess the risks of a project. Further practical advantages of CoBRA are its high level of interpretability and its transparency. While our previous studies have shown that a modified CoBRA called Web-CoBRA produces higher prediction accuracy, the method was not fully adopted by our industry partner because of its complex application steps when it is manually performed. In this paper, we report on our experiences with further automating Web-CoBRA based software cost estimation for a software company. It supports group decision-making processes by utilizing a wideband Delphi technique. We identify a range of problems when applying Web-CoBRA in the context of a software company and describe the approaches we used to solve these problems in our new tool called EffortWatch. Furthermore, we report on the evaluation and the effectiveness of EffortWatch using a technology acceptance model (TAM) questionnaire. The result is then compared with a previous study, showing EffortWatch drastically improves the use of the Web-CoBRA technique.