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:
The following diagram illustrates some features of Use Case diagrams:
Toolbox Elements and Connectors
Click on the following elements and connectors for more information.
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.