Roles of the actors in the system can be depicted. The main purpose of a use case diagram is to show what system functions are performed for which actors. A use case is an external view of the system that represents some action the user might perform in order to complete a task. The two main components of a use case diagram are use casesand actors.Īn actor represents a user or another system that will interact with the system we are modeling. A use case diagram displays the relationship among actors and use cases.
Generally, both graphical notation and descriptions are important as they document the use case, showing the purpose for which an actor uses a system.Ī use case is a set of scenarios that describing an interaction between a user and a system. One complaint about the standards has been that they do not define a format for describing these use cases. Both the UML and SysML standards define a graphical notation for modeling use cases with diagrams. Use Case diagrams are formally included in two modeling languages defined by the OMG. Its purpose is to present a graphical overview of the functionality provided by a system in terms of actors, their goals (represented as use cases), and any dependencies between those use cases. In software engineering, a Use Case Diagram is a type of Behavioral UML diagram defined by and created from a Use-case analysis.
