- An activity diagram is a type of flowchart with additional support for parallel behavior.
- This diagram explains the overall flow of control.
- An activity diagram is another important diagram in UML to describe dynamic aspects of the system.
- Activity diagram is basically a flowchart to represent the flow from one activity to another activity
- The activity can describe as an operation of the system.
- The control flow is drawn from one operation to another. This flow can sequential, branched or concurrent. This distinction important for a distributed system.
- Activity diagrams deal with all type of flow control by using different elements like the fork, join etc.
Purpose of Activity Diagrams
- Contrary to use case diagrams, in activity diagrams it is obvious whether actors can perform business use cases together or independently from one another.
- Activity diagrams allow you to think functionally.
When to use Activity Diagrams
- Activity diagrams are most useful when modeling the parallel behavior of a multithreaded system or when documenting the logic of a business process.
- Because of it possible to explicitly describe parallel events, the activity diagram well suited for the illustration of business processes, since business processes rarely occur in a linear manner and often exhibit parallelisms.
- This diagram useful to investigate business requirements at a later stage.
- An activity diagram is drawn from a very high level. So it gives the high-level view of a system. This high-level view is mainly for business users or any other person who is not a technical person.
- This diagram used to model the activities which nothing but business requirements.
- So the diagram has more impact on business understanding rather implementation details.