Frank Vogelezang, Eric van der Vliet, René Nijland, Eltjo Poort, Harry Mols, Jelle de Vries

Non-Functional Requirements determine a significant amount of the cost and effort that are needed to realize or maintain a software engineering solution. Yet the effect of Non-Functional Requirements on cost and effort estimates is largely underexposed in Software Engineering research.

A few estimating solutions have been proposed but yield unsatisfactory predictive power or lack a theoretical foundation of their mechanisms. From our earlier research on packaged software estimation we have derived that the basic mechanisms that drive the estimation of cost and effort from both Functional and Non-Functional Requirements are more complex than the currently proposed methods.

In this paper we present why in most cases only Architecture Driven Estimation mechanisms can lead to good cost predictions and we explain why current estimating solutions are unsuccessful.