Artifact: Use Case

This artifact captures the sequence of actions a system performs that yields an observable result of value to those interacting with the system.

Domains: Requirements
Work Product Kinds: Model Element, Specification

Purpose

The primary purpose of the Use Case is to capture the required system behavior from the perspective of the end user, to achieve one or more goals. Different users benefit in different ways, of course:

Customers use them to describe, or at least to approve, the description of the system's behavior.
Potential users use them to understand the system's behavior.
Architects use them to identify architecturally significant functionality.
Developers use them to understand the required system behavior so they can identify classes from the Use Cases' flow of events.
Testers use them as a basis for identifying a subset of the required Test Cases.
Managers use them to plan and assess the work for each iteration.
Technical writers use them to understand the sequence of system behavior that they need to describe in the documentation.

Relationships

Container Artifact	Use-Case Model
Roles	Responsible:	Modified By: Analyst Developer
Tasks	Input To: Create Test Cases Create Test Cases Design the Solution Detail Requirements Detail Requirements Refine the Architecture Implement the Solution Outline the Architecture Outline the Architecture	Output From: Detail Requirements Detail Requirements Find and Outline Requirements Find and Outline Requirements Implement the Solution
Process Usage	Agree on the Technical Approach > Use Case Agree the Technical Approach > Use Case Construction Phase Iteration > Identify And Refine Requirements > Use Case Construction Phase Iteration > Develop Solution (for requirement) (within context) > Use Case Construction Phase Iteration > Identify and Refine Requirements > Use Case Construction Phase Iteration > Develop Solution Increment > Use Case Develop Solution (for requirement) (within context) > Use Case Develop Solution Increment > Use Case Develop Solution Increment (no TDD) > Use Case Develop the Architecture > Use Case Develop the Architecture > Develop the Solution > Use Case Develop the Architecture > Use Case Develop the Architecture > Develop Solution Increment > Use Case Elaboration Phase Iteration > Identify and Refine Requirements > Use Case Elaboration Phase Iteration > Develop the Architecture > Use Case Elaboration Phase Iteration > Develop Solution (for requirement) (within context) > Use Case Elaboration Phase Iteration > Identify and Refine Requirements > Use Case Elaboration Phase Iteration > Develop the Architecture > Use Case Elaboration Phase Iteration > Develop Solution Increment > Use Case Identify and Refine Requirements > Use Case Identify and Refine Requirements > Use Case Inception Phase Iteration > Identify And Refine Requirements > Use Case Inception Phase Iteration > Agree on the Technical Approach > Use Case Inception Phase Iteration > Identify and Refine Requirements > Use Case Inception Phase Iteration > Identify and Refine Requirements > Use Case Inception Phase Iteration > Agree on the Technical Approach > Use Case Inception Phase Iteration > Agree on the Technical Approach > Use Case Inception Phase Iteration > Develop Architecture Spike > Use Case OpenUP lifecycle > Construction Iteration [1..n] > Identify and Refine Requirements > Use Case Transition Phase Iteration > Develop Solution (for requirement) (within context) > Use Case Transition Phase Iteration > Develop Solution Increment > Use Case

Illustrations

Templates	Use-Case Specification
Examples	Use-Case Specification

Tailoring

Representation Options

Decide the extent to which you will elaborate on Use Cases:

Describe only major flows?
Describe only the most important Use Cases?
Fully describe preconditions and post-conditions?
Describe scenarios first, and then raise the level of abstraction by describing Use Case flows?

Some projects apply Use Cases informally to help discover requirements, documenting and maintaining these requirements in another form such as user stories. How you tailor Use Cases may depend on project size, team experience, your tool set, the customer relationship, and so forth. See Guideline: Detail Use Cases and Scenarios for guidance related to documenting Use Cases.

More Information

Checklists	Use Case
Concepts	Use Case

This program and the accompanying materials are made available under the
Eclipse Public License v1.0 which accompanies this distribution.