Usage relationships

In UML modeling, a usage relationship is a type of dependency relationship in which one model element (the client) requires another model element (the supplier) for full implementation or operation.

The usage dependency does not specify how the client uses the supplier.

Usage relationships usually do not have names.

As the following figure illustrates, a usage relationship is displayed in the diagram editor as a dashed line with an open arrow, which points from the client model element to the supplier model element. The keyword «use» is displayed beside the connector.

Class2 uses Class1.