The third article will discuss how to write use cases that detail the scenarios that the users will be performing. We'll describe how to write complete and unambiguous use cases that describe individual aspects of system usage without presuming any specific design or implementation. Use case modeling involves working inward from the user requirements to start building a dynamic model of the solution space for the proposed system. We'll talk about how use cases, by extension, drive the entire development effort. This involves analyzing the narrative text of use cases, identifying a first-guess set of objects that will participate in those use cases, and classifying these objects based on the roles they play.
Boundary objects are what actors use in communicating with the system.
Entity objects are usually objects from the domain model. We'll show how robustness analysis, which serves as preliminary design within the process, provides the missing link between analysis and detailed design. The fifth and last article will discuss interaction modeling, the phase in which people build the threads that weave their objects together and enable them to start seeing how the new system will perform useful behavior. Allocate behavior among boundary objects, entity objects, and controllers that will become full objects in the model. Show the detailed interactions that occur over time among the objects associated with each use case.