The Concepts

This section introduces UML, object-oriented, database, and other concepts (such as the business modeling concepts, which are based on the Rational Unified Process developed by Rational Software Corporation). For a more complete discussion and more rigorous definitions of UML concepts, see Booch et al. [1999].

Actor ” an external person or system that interfaces with (that is, uses or is used by) the system

Use case ” a complete flow of actions, initiated by an actor, that the system performs to provide value to that actor

Business actor ” an actor that is external to the business

Business use case ” a use case, initiated by a business actor, that the business performs

Business worker ” an actor that is internal to the business whose work helps realize a business use case

Business entity ” something used by a business worker when fulfilling a use case

Business model ” a model that describes the business operation, composed of the business use case model and the business object mode

Business use case model ” a use case model that describes the business functions from a business actor's point of view; an external view of the business

Business object model ” an object model that provides the realization of a business use case; an internal view of the business

Use case diagram ” a diagram that shows use cases and their relationships with actors and other use cases

Class diagram ” a diagram that shows classes, their interrelationships, and their relationships with other model elements

Sequence diagram ” a diagram of collaborating objects and the messages they send to each other, arranged in time order, that shows how use cases are realized

Association ” a relationship between two model elements

Generalization ” a relationship between model elements indicating that one element (subclass) is a type of another element (superclass)

Aggregation ” a relationship between model elements indicating that one element is a part of another element (aggregate)