The use case diagram
- Actor: People, systems, and devices that have a stake in the successful operation of the system.
- System: Sets the context of the system in relation to the actors who use it and the features it must provide.
- Use case: Identifies the key features of the system. Without these features, the system will not fulfill the user/actor requirements. Each use case expresses a goal that the system must achieve.
- Association: Identifies an interaction between elements.
Elements of a Use Case Diagram
A use case diagram captures the business processes carried out in the system. Normally, domain experts and business analysts should be involved in writing use cases.
Use cases are created when the requirements of a system need to be captured and a use case diagram is quite simple in nature and depicts two types of elements:
- one representing the business roles and
- the other representing the business processes.
