Summary of Activity Diagram

In this session, you learnt about activity diagrams, which are drawn after use case diagrams:

1. For the pictorial representation of use case specification,
2. To show the order of execution of use cases, and
3. To show constraints on use cases.

Then, you learnt about action, which is a single unit of behavior that is performed in a system. You also got familiar with the concepts of initial node and activity final node.

You also gained an understanding of decision nodes, which are used to represent decisions (if-else conditions) in an activity diagram. A decision node has one incoming flow and multiple outgoing flows, but the flow passes through only one of those outgoing flows.

Post that, you learnt about merge nodes, which are used to merge multiple inputs flows into a single output flow in an activity diagram.

You also understood the concepts of partitions, which are used to distinguish between various responsible parties and group the actions performed by the same responsible party.

Then, you learnt about fork and join, which are similar to decision nodes and merge nodes, respectively but differ in terms of concurrency.

Further, you were introduced to the concept of object flows, which help you see how objects are manipulated during the execution of an activity.