Creating a generalization
You can create a Generalization on a Class Diagram, Use Case Diagram or Profile Diagram:
• On a Class Diagram you can create a Generalization between two Actors, Activities, Classes, Data Types, Interfaces, Signals or Use Cases.
• On a Use Case Diagram you can create a Generalization between two Actors or Use Cases.
• On a Profile Diagram you can create a Generalization between two Stereotypes.
When a super item has two or more Generalizations to sub items shown on a diagram, you can align its Generalizations.
To create a generalization:
1. On an appropriate diagram, add the two items between which you want to create a Generalization.
The two items must be of the same type.
2. On the diagram's tab, click the 
Generalization button.
Generalization button.3. On the diagram, click the sub item.
4. On the diagram, click the super item.
5. If a popup menu appears, click the appropriate command to use an existing Generalization, or click New to create a new Generalization.
6. If you created a new Generalization, type the name of the Generalization, and then press the Enter key.
To align a super item's generalizations:
• Right-click one of the super item's Generalizations, and then click Align Generalizations.