UModel diagrams can be deleted in one of the following ways:
•In the Model Tree window (or Diagram Tree window, or Favorites window), right-click the diagram, and then select Delete from the context menu.
•Click the diagram in any of the windows mentioned above, and then press Delete.
Deleting a diagram does not remove any elements from the project except the diagram itself. To check if elements are used in any diagrams, right-click the package you would like to inspect, and select List elements not used in any diagram, see also Checking Where and If Elements Are Used.
For information about deleting elements from a diagram or from a project, see Deleting Elements.