OOP G3

• Use case (in behavioral terms)


  A description of a particular interaction or scenario involving a system, product, or service, emphasizing the behavior or actions of individuals or entities involved
• Use cases


  • Commonly employed in software development, systems engineering, and business analysis
  • Outline how users or actors interact with a system to achieve specific goals or tasks
  • Illustrate the sequence of steps or actions that a user performs and the corresponding responses of the system
• Elements of a behavioral use case

  • Actor(s)
  • Description
  • Preconditions
  • Steps or Actions
  • Postconditions
  • Alternate Paths or Exceptions
• Actor(s)


  The users or external systems interacting with the system under consideration, often represented as personas or roles with specific goals or tasks
• Description


  The specific scenario or task that the use case addresses, typically including a narrative or flow of actions that the actor(s) perform
• Preconditions


  The conditions or assumptions that must be true before the use case can be executed, often describing the state of the system or environment before the use case begins
• Steps or Actions


  The sequence of actions performed by the actor(s) and the system's responses at each step, described in detail to provide a clear understanding of the interaction
• Postconditions


  The state of the system or environment after the successful completion of the use case, specifying the outcomes or changes resulting from executing the use case
• Alternate Paths or Exceptions


  Alternative sequences of actions or exceptional scenarios that may occur during the execution of the use case, including handling errors, exceptions, or deviations from the main flow
• Use case diagram


  A visual representation in Unified Modeling Language (UML) that shows how users (actors) interact with a system to accomplish specific tasks (use cases)
• Use case diagrams


  • Aid in requirements analysis, communication, system design, and testing during the software development process
  • Provide a clear overview of system functionality
  • Help stakeholders understand and prioritize requirements effectively
• Actors


  Users or external systems represented in a use case diagram
• Use cases


  System functionalities represented in a use case diagram
• Relationships in use case diagrams

  Association, inclusion, and extension