In UML models, you can create an inheritance hierarchy
of a selected classifier, such as a class, interface, or use case. When
you create an inheritance hierarchy, you can view it while the model
is open. When you close the model, this information does not persist.
You must be in the Modeling perspective
and have a diagram that contains classifiers that support inheritance
open in the diagram editor.
To create the inheritance hierarchy for a classifier, in
the diagram editor, right-click a classifier; then click .
As the following figure illustrates, the hierarchy of
elements that inherit from the selected classifier, and the elements that
the selected classifier inherits, is displayed in the top section
of the Inheritance Explorer view. The list
of operation and attributes of the selected classifier is displayed
in the bottom section.

Tip: You can sort the list of operations and attributes
that is displayed in the bottom section of the Inheritance
Explorer view. You can also open inheritance hierarchies
that you created for other classifiers in the model, or create new
inheritance hierarchies in the Inheritance Explorer view.
After you have created an inheritance hierarchy for a classifier,
you can browse the displayed hierarchy in the Inheritance
Explorer view.