Diagrams represent visually how modeling elements interact, what is their structure, dependencies, hierarchy, and so on. Diagrams must belong to a package in the project, and therefore must be created under an existing package in the Model Tree window. You can move diagrams from one package to another at any time, by dragging them into a destination package.
To create a new diagram:
1.Right-click a package in the Model Tree window.
2.Select New Diagram | <Diagram Kind>.
You can also create a new diagram from the Diagram Tree window, as follows:
1.Right-click the root node ("Diagrams") in the Diagram Tree window.
2.Select a package where the diagram should belong, and click OK.
When the diagram window is active, the toolbars display only modeling elements applicable to the current diagram kind. The diagram kind is displayed in the Properties window after you click an empty area of the diagram. In addition to this, the following icons depict the diagram kind.
Composite Structure Diagram
Interaction Overview Diagram
Protocol State Machine Diagram
State Machine Diagram
Use Case Diagram
XML Schema Diagram