Linking soft systems and use-case modelling through scenarios

Scenarios are fundamental to the description and comprehension of systems of any type. They can therefore provide a common base when attempting to combine different modelling approaches. This paper considers their particular role in linking Soft Systems Methodology (SSM) and Use-case modelling. It does so in the context of examining the potential gain from using these techniques in combination. SSM supports strategic planning for business design or improvement. This involves the development of system models to identify the activities that an organisation must perform to meet its goals. Use-case modelling is a requirements engineering technique that similarly leads to the identification of system activities, but is driven more by the needs of the system's ‘users’ than those of the system itself. These different but complementary perspectives suggest that either technique can be used to help validate the other's models. This seems particularly valuable in the development of information systems. More significantly, however, SSM emerges as a way of enhancing Use-case development and UML in general.