Executable UML: A Foundation for Model-Driven Architecture

10.3. Visualizing Domain Dynamics

As the number of communicating state machines increases, we need a way to visualize the big picture of the domain dynamics. We use interaction diagrams of two kinds, a collaboration diagram that describes the communications between state machine instances without explicit regard to time, and sequence diagrams that describe objects in specific states over time.

Experienced modelers sketch collaboration and sequence diagrams before formalizing state machines to help organize the dynamics in the domain. Once the state machines have been constructed, the collaboration diagrams can be regenerated from the state machines themselves. The result could be sufficiently horrifying to cause reconstruction of the state machines, ...