[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.

Reference

• https://en.m.wikipedia.org/wiki/Use_case
• https://en.wikipedia.org/wiki/Use_case_diagram
• https://www.geeksforgeeks.org/use-case-diagram/
• https://www.ibm.com/docs/ko/rational-soft-arch/9.7.0?topic=diagrams-use-case