4.COLLABORATION DIAGRAM A collaboration diagram describes interactions among objects in terms of sequenced messages. Collaboration diagrams represent a combination of information taken from class, sequence, and use case diagrams describing both the static structure and dynamic behavior of a system. Symbols and NotationsClass rolesClass roles describe how objects behave. Use the UML object symbol to illustrate class roles, but don't list object attributes.
20 Messages Unlike sequence diagrams, collaboration diagrams do not have an explicit way to denote time and instead number messages in order of execution. Sequence numbering can become nested using the Dewey decimal system. For example, nested messages under the first message are labeled 1.1, 1.2, 1.3, and so on. A condition for a message is usually placed in square brackets immediately following the sequence number. Use a * after the sequence number to indicate a loop. 5. ACTIVITY DIAGRAM An activity diagram illustrates the dynamic nature of a system by modeling the flow of control from activity to activity. An activity represents an operation on some class in the system that results in a change in the state of the system. Typically, activity diagrams are used to model workflow or business processes and internal operation. Because an activity diagram is a special kind of state-chart diagram, it uses some of the same modeling conventions. Symbols and Notations Action states Action states represent the non-interruptible actions of objects. Action Flow Action flow arrows illustrate the relationships among action states.