Chapter 15. Collaborations
Unlike the other chapters in this book, this one does not correspond to an official diagram in UML 2. The standard discusses collaborations as part of composite structures, but the diagram is really quite different and was used in UML 1 without any link to composite structures. So I felt it best to discuss collaborations as their own chapter.
Let’s consider the notion of an auction. In any auction, we might have a seller, some buyers, a lot of goods, and some offers for the sale. We can describe these elements in terms of a class diagram (Figure 15.1) and perhaps some interaction diagrams (Figure 15.2).
Figure 15.1. A collaboration ...