An activity chart describes the functional view of the system using activities as the primary building block. This is sometimes referred to as the process-oriented view. A system description can contain one or more activity charts. Activity charts, which can be connected to module charts, describe the functionality of individual modules.
Activity charts can also be connected to statecharts, which either define the behavior of individual activities or control groups of activities as a control-activity.
The following sections describe in more detail how to use activity charts.