[UML](EN) Use Case Diagram
Use Case Diagram
Environment and Prerequisite
- UML
Use Case Diagram
Use Case
- Use Case: Text story which user use system to achieve a goal.
Use Case Diagram
- Use Case Diagram: Diagram which shows telationships between actors and use cases.
Actor, Use Case, System Boundary
Actor
- Actor: External entity which interacts with system.
- The diagram represents it with an human shape icon.
- In Use Case image, “Registered User” is an actor.
Use Case
- Check definition in Use Case.
- The diagram represents it with an oval.
- In Use Case image, “Edit an article.” is use case.
System Boundary
- System Boundary: System model to design.
- The diagram represents it with an rectangle.
- Use Case Diagram image, “System Boundary” is system boundary.
Relationship
Association
- Association: Shows interaction between actor and use case.
- Ex) User edit board.
Include
- Include: It refers to a relationship that one use case include another use case.
- Ex) Compose post includes adding image.
Extend
- Extend: It refers to a relationship that can extend to another use case when certain conditions are met.
- Ex) Flight reservation allows seat selection under certain conditions.
Generalization
- Generalization: It represents a concept similar to inheritance, where a use case is a generalized parent use case of other use cases.
