Use Case Diagram

A Use Case diagram captures Use Cases and relationships between Actors and the subject (system). It describes the functional requirements of the system, the manner in which outside things (Actors) interact at the system boundary, and the response of the system.

In developing a Use Case diagram, also consider:

Example Diagram

The following diagram illustrates some features of Use Case diagrams:

Example of a Use Case Diagram

Toolbox Elements and Connectors

Select Use Case diagram elements and connectors from the Use Case pages of the Toolbox.

Tip:

Click on the following elements and connectors for more information.

Use Case Diagram Elements

Use Case Diagram Connectors

e_Actor

c_Use

e_UseCase

c_Associate

e_testcase

c_Generalize

e_Collaboration

c_Include

e_BoundaryBox

c_Extend

e_Package

c_Realize

 

c_Invokes

 

c_Precedes

Note:

Invokes and Precedes relationships are defined by the Open Modeling Language (OML). They are stereotyped Dependency relationships; Invokes indicates that Use Case A, at some point, causes Use Case B to happen, whilst Precedes indicates that Use Case C must complete before Use Case D can begin.