Extension and partitioning of use cases in support of formal object modeling

The number of use cases produced for any non-trivial system can be large. These use cases may contain redundancies resulting from multilevel stakeholder communities, natural language ambiguity, terminology differences, and common data and behaviours. In order to prepare use cases for formal requirements modeling, some structure is needed to classify the use cases into partitions that are meaningful to the object modeler. This paper extends Jacobson's (1992) use cases with a refinement called system oriented use cases. The extensions are then partitioned according to the strength of their similarity: behavioural, intentional, and environmental. The partitioning is exhaustive and produces a hierarchy. The hierarchy is a useful input to bound the requirements modeling activity that follows the elicitation phase.