Chapter 5. Robustness Analysis

There are two major questions that help us link the dynamic model with the static model. The first question is: What objects do we need for each of these use cases? (We’ll pose the second question in Chapter 7.) We’ll use the robustness analysis technique originally developed by Ivar Jacobson to help answer this question.

A robustness diagram is similar to a UML collaboration diagram, in that it shows the objects that participate in the scenario and how those objects interact with each other. Robustness analysis is not exactly a core part of UML; instead, it requires the use of some stereotypes. Robustness analysis was part of Jacobson’s Objectory method; it’s an informal, “back of the envelope” kind of analysis that’s of enormous value in helping you refine use case text and discover objects that are needed, but that didn’t make it into the domain model.