chapter 3

• User Stories


  A one-sentence description of a work-related task done by a user to achieve some goal or result
• Acceptance Criteria


  Identify the features that must be present at the completion of the task
• User Story Template


  "As a <role> I want to <goal> so that <benefit>"
• Use Case


  An activity that the system performs, usually in response to a request by a user
• Identifying Use Cases


  1. User goal technique

  2. Event decomposition technique
• User Goal Technique


  • Simple and effective
  • Identify all potential categories of users
  • Interview users to find specific goals
• User Goal Technique Steps

  1. Identify potential users

  2. Classify users by role and organizational level

  3. Interview users to find goals

  4. Create preliminary use case list

  5. Resolve duplicates and inconsistencies

  6. Identify shared use cases

  7. Review with users and stakeholders
• Event Decomposition Technique


  • More comprehensive and complete
  • Identify events that require system response
  • Name use case for each event
• Event Decomposition Technique Steps

  1. Consider external events

  2. Name use cases for external events

  3. Consider temporal events

  4. Name use cases for temporal events

  5. Consider state events

  6. Name use cases for state events

  7. Apply perfect technology assumption
• Elementary Business Process (EBP)


  A fundamental business process performed by one person, in one place, in response to a business event
• Use Case Description


  A brief one sentence description showing the main steps
• Use Case Diagram


  A UML model used to graphically show use cases and their relationships to actors
• Actor


  The UML name for an end user
• Automation Boundary


  The boundary between the computerized portion of the application and the users who operate the application
• <<includes>> Relationship


  A relationship between use cases where one use case is stereotypically included within the other use case
• Creating Use Case Diagrams

  1. Identify stakeholders and users who need to see the diagram

  2. Determine what each needs to review

  3. Select use cases and actors to show

  4. Name the diagram and note how/when to use it
• This chapter focuses on modeling functional requirements through use cases
• Use cases are the functions identified, the activities the system carries out usually in response to a user request
• The user goal technique and event decomposition technique are two techniques for identifying use cases
• The user goal technique identifies user goals, the event decomposition technique identifies events that require system response
• Three types of events are external, temporal, and state events
• The use case diagram shows the actors, automation boundary, use cases, and <<includes>> relationships
• Use case diagrams are drawn based on the presentation needs of the analysis