Use cases is a powerful technique for the elicitation and documentation of black-box functional requirements.

The system boundary defines the system of interest in relation to the world around it. The relationships between and among the actors and the use cases. Use cases are typically initiated by a user to fulfill goals describing the activities and variants involved in attaining the goal. Use CaseĪ use case describes how actors uses a system to accomplish a particular goal.

The actor can be a human or other external system. A use case diagram contains four main components ActorĪctors are usually individuals involved with the system defined according to their roles. Use cases define interactions between external actors and the system to attain particular goals. Describes one main flow of events (main scenarios) and possibly other exceptional flows (alternatives), also called paths or user scenarios.Models the goals of system/actor (user) interactions.While a use case itself might drill into a lot of detail (such as, flow of events and scenarios) about every possibility, a use-case diagram can help provide a higher-level view of the system, providing the simplified and graphical representation of what the system must actually do.Ī use case (or set of use cases) has these characteristics: A use case is made up of a set of possible sequences of interactions between systems and users that defines the features to be implemented and the resolution of any errors that may be encountered. A use case is a useful technique for identifying, clarifying, and organizing system requirements. Developed by analysts together with domain expertsĪ use case is a list of actions or event steps typically defining the interactions between a role of an actor and a system to achieve a goal.Drive implementation and generate test cases.Use case diagrams are typically develop in early stage of development and people often apply use case modeling for the following purposes:

In 1992 his co-authored book Object-Oriented Software Engineering - A Use Case Driven Approach helped to popularize the technique for capturing functional requirements, especially in software development.

In 1986, Ivar Jacobson first formulated textual and visual modeling techniques for specifying use cases.These days use case modeling is often associated with UML, although it has been introduced before UML existed. Online Store Use Case Diagram Origin of Use Case A use case diagram consists of the system, the related use cases and actors and relates these to each other to visualize: what is being described? ( system), who is using the system? ( actors) and what do the actors want to achieve? ( use cases), thus, use cases help ensure that the correct system is developed by capturing the requirements from the user’s point of view. A use case describes how a user uses a system to accomplish a particular goal.

Use case diagram online store