Illustrating Relationships in Use Case Diagrams
In UML, relationships are connections between model elements. Use cases are also connected to each other in different kinds of relationships. The relationship between two use cases basically models the dependencies between two use cases. By reusing existing use cases using different types of relationships, the overall effort required to develop the system is reduced.
Use case diagrams show use cases, actors, and the relationships between them. For example, the relationship between an actor and a use case illustrates that the actor can use a certain functionality of the business system.
