Learning UML 2.0

Chapter 10. Completing the Interaction Picture: Interaction Overview Diagrams

Ever been asked to “look at the bigger picture”? Whether you are working on a new idea or modeling in UML, sometimes it helps to take a step back from the details to get a better feel for what you are doing and the context within which you are doing it. This is the job of interaction overview diagrams; they exist to give you that big picture perspective on your system’s interactions.

Interaction overview diagrams provide a high-level view of how several interactions work together to implement a system concern, such as a use case. Sequence, communication, and timing diagrams focus on specific details concerning the messages that make up an interaction, but interaction overview diagrams tie together the different interactions into a single complete picture of the interactions that make up a particular system concern.

An interaction overview looks very much like an activity diagram (see Chapter 3) except that each of the actions are interactions within their own right. Think of each part of an interaction overview as a complete interaction in itself. If one interaction within the overview is most concerned with timing, then a timing diagram could be employed (see Chapter 9), while another interaction of the overview may need to focus on message ordering, and so a sequence diagram could be used (see Chapter 7). The interaction overview glues together separate interactions within your system in the notation that ...