Concept
The Use Case Diagram describes the behavior of a system from a user's
standpoint : functional description and its major processes.
It provides a graphic
description
of who will use a system and what kind of interactions to expect
within that
system. Use Case Diagrams are useful when describing requirements for a
system
in the analysis, design, implementation and documentation stages.
A Use Case Diagram is a collection of actors, Use Cases, and their
communications.
The elements of the Use Case diagrams are available in the tool bar:
New Actor can be created by selecting
the icon in the toolbar.
New Use Case can be created by selecting
the icon in the toolbar.
New system can be created.
Create inheritance relationships
between Use Cases or actors.
The Includes Relationship is
used to indicate that the source Use Case includes the behavior of the
target Use Case.
The Extends Relationship
indicates that the source Use Case adds its behavior to the target Use
Case.
Association is linking
an actor to its Use Cases.