Software Fortresses: Modeling Enterprise Architectures

2.4. Sequence–Ally Diagram

FADs and TADs are good for getting a high-level view of fortress relationships. They do not go into detail about the sequence of events that link fortresses as a treaty unfolds. To see better how the allied fortresses coordinate their workflow to fulfill the overall treaty requirements, we use a sequence–ally diagram (SAD).

SADs are adaptations of the UML construct called class sequence diagrams. A SAD gives an overview of a single treaty. In a SAD, the heading of the card gives the name of the treaty. Within the treaty, each ally fortress is represented by a vertical line. Interactions between the fortresses are shown with one of three arrows, following conventions similar to those used in UML's class sequence diagrams. ...