Toward an effort estimation model for software projects integrating risk

According to a study of The Standish Group International, 44% of software projects cost more and last longer than expected. More accurate the effort estimation is; the better the enterprise gets organized and the more the software project respects the commitments on budget, time and quality. Enhancing the accuracy of effort estimation remains an ongoing challenge to software professionals. Several factors can influence the accuracy of effort estimation, namely the immaterial aspect of information system projects, new technologies and the lack of return on experience. However, the most important factor of cost and delay increase is software risks. A software risk is an uncertain event with a negative consequence on the software project. In this article, we propose a methodology to take into account risk exposure analysis in the effort estimation model. In the literature, this issue is little addressed and few approaches are investigated. In this research work, we first present an overview of these approaches and their limits. Then, we propose an effort estimation model that improves the accuracy of estimation by integrating software risks. We finally apply this model to a case study and compare its results to the results of a classic model.