A usability-oriented approach to requirements engineering

We describe and propose a usability-oriented approach to requirements engineering, the Delta method. We suggest that by focusing primarily on the tasks that the users are supposed to accomplish using a system, rather than the functionality of the system, functional requirements are elicited in a natural way and in their right context. The Delta method was developed in collaboration with a consultancy firm and validated in a commercial project. The components of the Delta method are outlined and discussed. The method is described further in a case study, and the results of this industrial application are reported.