The previous posts Death of the Actor and Death of the Use Case reported about two serious killings in the modeling scene. Many eyewitnesses commented the report. Now it is time for a short review. First the good news: The concepts Actor and Use Case survived the massacre. I’ve seen them still alive and very active in many projects. Sadly the SysML/UML model element Actor is dead – rest in peace – and the modeling element UseCase is in intensive care. The concept Actor...

After killing the Actor in The Death of the Actor my next victim is the use case. Don't use Use cases in SysML (or UML) models anymore! My statement seems to be revolutionary or stupid (or both). Just to be not misunderstood, I'm not against the concept of use cases and actors. I believe that the SysML model elements Actor and UseCase are not necessary and useful. I've already explained it for the Actor in my previous post The Death of the...

The technical term System is relative and depends on the viewpoint. From one viewpoint an entity is a system, from another one it is a subsystem or an external system. It is a role that is applied to an entity. You loose this flexibility of changing the viewpoint if you model a system context with SysML and the model elements Block (for the system) and Actor (for the users and external systems). By definition, the model element Actor represents an...