Guidelines: Activity Diagram in the Business Use-Case Model

Activity Diagram

An activity diagram in the business use-case model illustrates the workflow of a business use case.

The workflow of a business use case describes what needs to be done by the business to provide the value the served business actor is looking for. It consists of a sequence of activities that together produce something for the business actor. The workflow often consists of a basic flow, and one or several alternative flows.

The workflow of a business use case can be described graphically with the help of an activity diagram. Such a diagram shows:

• Action states, which represent the execution of an activity or step within the workflow.
• Transitions between those action states.
• Decisions for which a set of guard conditions are defined. These guard conditions control which transition that follows once the activity an action state represents has been completed.

An activity diagram for the business use case Individual Check-In in the business use-case model of airport check-in.

Activity diagram is a special case of a state diagram in which all or most of the states are action states and in which all or most of the of the transitions are triggered by completion of actions in the source states.