Summary of Use Case Diagram

In this session, you learnt the concept of a use case diagram. You also gained an understanding of the use cases that are used to represent the functionalities that the system will perform. Then, you learnt about actors, which represent the external entities that interact with your system.

You also got familiar with the concept of association, which is used to connect actors with their respective use cases. Further, you got an idea of the concept of system boundary, which is used to represent what is internal to the system and what is external.

Then, you learnt about three types of relationships between use cases:

1. Include relationship, where included use cases have to be executed before the including use case can execute.
2. Extend relationship, where the extending use cases may or may not get executed before the extended use case gets executed.
3. Generalisation relationship, where the common behaviour of different use cases can be captured into one general use case.