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. Describes one main flow of events (main scenarios) and possibly other exceptional flows (alternatives), also called paths or user scenariosĪctors are usually individuals involved with the system defined according to their roles.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.

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.Ī 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. View and play PowerPoint presentations online.Ī use case describes how a user uses a system to accomplish a particular goal.

Online use case diagram