Use Case Diagrams

A use case diagram shows a set of use cases and actors and the relationships among them. Figure 4-10 shows an example of a use case diagram.

Figure 4-10: Use case diagram

It's a good idea to draw one use case diagram per actor. You can also use different layers of use case diagrams to good effect. For example, you might have an "executive summary" layer that shows only the use cases of most general interest, and then subsequent layers would show more specialized use cases.