The Emperor's New Use Case
By: Gonzalo Génova, Juan Llorens
In UML, use cases are meta-modeled as classifiers. Classifiers specify a set of instances, and use case instances are said to be concrete system-actor interactions. But it is not clear how an interaction can have classifier features such as attributes, operations and associations. Therefore, we challenge the notion that use case instances are interactions. We also propose a notion of use case (a coordinated use of system operations) that is very close to the traditional protocol, therefore concluding that use cases and protocols are not essentially different things.