Requirements Exploration by Comparing and Combining Models of Different Information Systems

A people or an organization participates in several different activities simultaneously. Some activities are already supported by information systems, and others are not yet supported but supposed to be. In this paper, we proposed and exemplified a method for exploring the efficiency and synergy of the systems by comparing and combining system elements. We use any modeling languages such as use case diagrams and data flow diagrams for this comparison and combination. For the efficiency, elements in a model are shared or substituted by/for those in another. For the synergy, elements in several models are combined so as to resolve the problems of stakeholder. To validate and discuss our method, we applied it to three sets of activities: room and seat booking, driving and taxi, and rainy report and wiper control. Three different notations are used for each case: use case diagrams, activity diagrams and data flow diagrams.