The set of interfaces realized by a classifier is its provided interfaces, which represent the obligations that instances of that classifier have to their clients. They describe the services that the instances of that classifier offer to their clients.

The interfaces may also be used to specify required interfaces, which are specified by a usage dependency between the classifier and the corresponding interfaces. Required interfaces specify services that a classifier needs in order to perform its function and fulfill its own obligations to its clients.


To draw a Provided Interface


  1. In the Class diagram, create a Class.
  2. Select the Class shape and in the smart manipulator toolbar, click Interface Realization and then click on the diagram pane. The provided interface is created.
  3. Select the interface shape, click the Compartments smart manipulator button, and then select Suppress All. Alternatively, click the Suppress All button in the diagram toolbar. 

To draw a Required Interface


  1. In the Class diagram, create a Class.
  2. Select the Class shape and on the smart manipulator toolbar, click the Usage button and then click on the diagram. The required interface is created.
  3. Select the interface shape, click the Compartments smart manipulator button, and then select Suppress All. Alternatively, click the Suppress All button in the diagram toolbar.