Why Activity Diagram is Important in OOAD?

In the next video, you will be introduced to the concept of an activity diagram.

So now, you know that activity diagrams are used:

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

Video Transcript

Activity diagrams. Let's now see what the what and why of an activity diagram. An activity diagram is a pictorial representation of your use case specifications. A use case could have a multiple specifications doing all those fine details. If those specifications has to be represented in a diagrammatic fashion, that's when active D diagram comes into play. Next, it also shows the order in which different use cases are executed. Finally, it also shows the constraints on the use cases. For example, if we have a use case of a login logout, what if a user enters a wrong password? What if a user forgot his password or he wishes to change his password? All these are some constraints and some special case handlings in a within a use case. These cases are also represented using an activity diagram.

Video Recap

• An activity diagram represents use case specifications pictorially.

• It helps to represent multiple use case specifications in a diagrammatic manner.

• The diagram shows the order in which different use cases are executed.

• It also displays constraints on the use cases, such as special case handling for login/logout.

• Activity diagrams help to represent the flow of a process or system and are useful for software development and business process modeling.