Abstract
Outsourcing software development work activities has brought many benefits to
software development projects, such as, reduced development cost and time. Managing the
application of this strategy is a key characteristic in its own or in its implications. Accurate
effort estimation is crucial to software development projects success, especially in globally
distributed projects. Therefore, it is necessary to identify and to investigate the underlying
factors which influence the accuracy of effort estimation methods. In this paper, we will
investigate the COCOMO II, SLIM and ISBSG effort estimation methods. Furthermore, the
ISBSG method supports the experts’ judgment estimation for effort as a candidate effort
estimation method representing the expert judgment with accuracy in estimating the
required amount of effort to accomplish a given project within the context of globally
distributed projects.