From Use Cases to Activity Cases

Use cases can be used to capture requirements and to subdivide IT-systems into functionally coherent units. Information systems are activity systems that carry out important business activities. Many systems development methods recognize activity modeling as an important development activity. Use cases are based on a set of assumptions that makes them unsuitable for general activity modeling. The purpose of the paper is to analyze the strengths and weaknesses of use cases with respect to activity modeling. We introduce activity cases as a more general modeling tool that can be used to supplement use cases. Activity cases should not be seen as alternatives to existing activity modeling languages. They should be seen as modeling frameworks that focus on the common properties of existing languages.