Artifact: Use Case
This artifact captures the system behavior to yield an observable result of value to those who interact with the system.
Domains: Requirements
Purpose

Use cases are used for the following purposes:

  • To reach a common understanding of system behavior
  • To design elements that support the required behavior
  • To identify test cases
  • To plan and assess work
  • To write user documentation.
Relationships
Description
Brief Outline

A use case typically includes the following information:

  • Name: The name of the use case
  • Brief Description: A brief description of the role and purpose of the use case
  • Flow of Events: A textual description of what the system does in regard to a use case scenario (not how specific problems are solved by the system). Write the description so that the customer can understand it. The flows can include a basic flow, alternative flows, and subflows.
  • Key scenarios: A textual description of the most important or frequently discussed scenarios
  • Special Requirements: A textual description that collects all of the requirements of the use case that are not considered in the use-case model, but that must be taken care of during design or implementation (for example, non-functional requirements)
  • Preconditions: A textual description that defines a constraint on the system when the use case starts
  • Post-conditions: A textual description that defines a constraint on the system when the use case ends
  • Extension points: A list of locations within the flow of events of the use case at which additional behavior can be inserted by using the extend-relationship
Illustrations
Tailoring
Impact of not havingWithout this artifact, it might be unclear which functionality the solution needs to support.
Reasons for not needingYou might not need to use a use case if your project uses alternative requirements practices (for example, "The system shall..." statements).
Representation Options

You can document the use case as a use-case specification document or you can incorporate the use case in a use-case model. You can also use a requirements management tool to capture use cases and parts of use cases.

More Information
Checklists
Concepts