About Use Case Diagram View

A use case diagram view describes the interactions that take place between actors and systems during the execution of processes. The actions of the system are analyzed from user's viewpoint.

This page discusses:

Use Case Diagram View Structure

A use case diagram view is always created in a sheet. This sheet can be attached to a function or a logical reference.

Elements of a Use Case Diagram View

In a use case diagram view, you can insert different elements.

Actors

Something with a behavior or role, such as a person, another system or, an organization.

Use Cases

A use case represents a function or logical reference or an action within the system.

System

The system is used to define the scope of the use case.

Relationships

There are four types of relationships between use cases:

  • Association: a connection between an actor and a use case.
  • Generalization: one element called the child is based on another element called the parent.
  • Include: One use case includes the functionality of another use case.
  • Extend: One use case extends the behavior of another use case.

Example

This example illustrates a use case diagram view.

Implement Relations

Implement relations can be created:

  • a reference-reference link between a use case and a functional or logical reference.
  • an occurrence-occurrence link between sub use case and a functional or a logical instance.
Note: For more information about implement links, see Creating Implement Relations.