Deriving requirements from process models via the problem frames approach

Jackson's problem frames is an approach to describing a recurring software problem. It is presumed that some knowledge of the application domain and context has been gathered so that an appropriate problem frame can be determined. However, the identification of aspects of the problem, and its appropriate 'framing' is recognised as a difficult task. One way to describe a software problem context is through process modelling. Once contextual information has been elicited, and explicitly described, an understanding of what problems need to be solved should emerge. However, this use of process models to inform requirements is often rather ad hoc; the traceability from business process to software requirement is not always as straightforward as it ought to be. Hence, this paper proposes an approach for deriving and contextualising software requirements through use of the problem frames approach from business process models. We apply the approach on a live industrial e-business project in which we assess the relevance and usefulness of problem frames as a means of describing the requirements context. We found that the software problem did not always match easily with Jackson's five existing frames. Where no frame was identified, however, we found that Jackson's problem diagrams did couch the requirements in their right context, and thus application of the problem frames approach was useful. This implies a need for further work in adapting a problem frames approach to the context of e-business systems.