Claudio De Sio Cesari --- Use Case Diagram Syntax Reference --- http://www.claudiodesio.com

Use Case Diagram Syntax Reference

Element name

Syntax

Synopsis

Actor

Alternative

Actor: role performed by user with the system.
PS: a user could not be human.

PS: a user could not be a human.

Use Case

Alternative

Use case: set of scenarios for a user common target.

A scenario is a steps sequence describing the interaction beetween the user and the system.

PS: It is possible to describe scenarios with dynamic diagrams.

Relationship link

Alternative

Relationship link : logical relationship link beetween an actor and a use case.

System Boundary

System boundary : system domain limit.

Inclusion

Inclusion: logical relationship link between use cases, that extract a common behavior for more use cases.

Extension

Alternative

Extension: logical relationship link beetween use cases with the same semantic target. The specialized use case, reach his target adding extension points, written in the base use case.

Extension point : describes a specialized use case behavior, not used by the base use case.

Generalization

Generalization: logical relationship link beetween use cases, with the same semantic target. The specialized use case, reach his target adding new behaviors not used by the base use case, but without syntax formalisms.

Actor generalization

Alternative

Actor generalization : logical relationship link beetween actors. A specialized actor, can relate himself with any use case related with the base use case. Then it can be related with other use cases that are not related with the base use case.

Claudio De Sio Cesari --- Use Case Diagram Syntax Reference --- http://www.claudiodesio.com