IN THIS CHAPTER

Having defined the project vision, the actors, and the events of interest in the system, we next move to assigning the events to use-cases. The use-case is the one UML artifact that focuses on what the system will be contracted to do, not how it will do it. Use-cases are the hub from which all requirements are derived.

Every event identified in Chapter 3 as part of the Inception phase must be satisfied by a use-case. One use-case can satisfy many events. As a result, a use-case may have more than one pathway through it. A pathway is the set of steps that must be carried out to satisfy the goal of the actor. This chapter examines how to identify these pathways, and it describes in detail the primary pathway through each use-case.

The chapter also investigates a preliminary software architecture. This architecture is based on what is known about the application's execution domain and is represented by the UML component and deployment diagrams.

The Inception phase will also produce an estimate of both the number of iterations and increments in which the system will be realized and the time and costs incurred for deliverables. This grouping of functionality is visualized with the UML package diagram.