Model-Based Specification and Validation of User Interface Requirements

Core functional requirements as captured ill use case models are too high-level to be meaningful to user interface developers. In this paper we present how use case models can be systematically refined into detailed user interface requirements specifications, captured as task models. We argue that the transition from functional to UI specific requirements is a semi-formal step which necessitates experience, skills and domain knowledge of the requirements engineer. In order to facilitate the transition we sketch out an integrated development methodology for use case and task models. Since the engineer is also responsible for establishing conformity between use cases and task models we also show, how this validation call be supported by means of the WTM task model simulator.