Icon class icon_class fas fa-quote-left icon_class_computed fas fa-quote-left Related content Source Unified Modeling Language 2.5.1 Copyright information About Object Management Group copyright in text extracts quoted from OMG specifications for educational purposes Snippet kind INFO UML keywords UseCase UseCase::subject Keywords functional requirement external requirement Previous snippet Full quote UseCases can be used both for specification of the (external) requirements on a subject and for the specification of the functionality offered by a subject. Next snippet Moreover, the UseCases may also state the requirements the specified subject poses on its environment by defining how the Actors should interact with the subject so that it will be able to perform its services. Related snippets A subject for a set of UseCases (sometimes called a system boundary) may be shown as a rectangle with its name in the top-left corner, with the UseCase ellipses visually located inside this rectangle. A UseCase may apply to any number of subjects. When a UseCase applies to a subject, it specifies a set of behaviors performed by that subject, which yields an observable result that is of value for Actors or other stakeholders of the subject. A UseCase is a kind of BehavioredClassifier that represents a declaration of a set of offered Behaviors. Each UseCase specifies some behavior that a subject can perform in collaboration with one or more Actors. UseCases define the offered Behaviors of the subject without reference to its internal structure. These Behaviors, involving interactions between the Actors and the subject, may result in changes to the state of the subject and communications with its... A subject of a UseCase could be a system or any other element that may have behavior, such as a Component or Class. Each UseCase specifies a unit of useful functionality that the subject provides to its users (i.e., a specific way of interacting with the subject). This functionality must always be completed for the UseCase to complete. Related snippets (backlinks) The behaviors of a UseCase can be described by a set of Behaviors (through its ownedBehavior relationship), such as Interactions, Activities, and StateMachines, as well as by pre-conditions, post-conditions and natural language text where appropriate. It may also be described indirectly through a Collaboration that uses the UseCase and its Actors as the Classifiers that type its parts. UseCases may have associated Actors, which describe how an instance of the Classifier realizing the UseCase and a user playing one of the roles of the Actor interact. Two UseCases specifying the same subject cannot be associated as each of them individually describes a complete usage of the subject. A UseCase may be owned either by a Package or by a Classifier. Although the owning Classifier typically represents a subject to which the owned UseCases apply, this is not necessarily the case ... Visit also Visit also (backlinks) Flags
