Applying UML and Patterns: An Introduction to Object-Oriented Analysis and Design and the Unified Process, Second Edition

15.1. Sequence and Collaboration Diagrams

The term interaction diagram is a generalization of two more specialized UML diagram types; both can be used to express similar message interactions:

• collaboration diagrams

• sequence diagrams

Throughout the book, both types will be used, to emphasize the flexibility in choice.

Collaboration diagrams illustrate object interactions in a graph or network format, in which objects can be placed anywhere on the diagram, as shown in Figure 15.1.

Figure 15.1. Collaboration diagram.

Sequence diagrams illustrate interactions in a kind of fence format, in which each new object is added to the right, as shown in Figure ...