The parent of a 'Class' construct can be assigned in the 'Class Diagram' via drag-and-drop. Both the “to-be” parent and child 'Class' constructs must be added to the diagram first, before the parent can be assigned.

1. Within a 'Class Diagram,' select the 'Class' you would like to assign as the parent.
2. Click the green circle and continue to hold down the left mouse button.
3. Drag the green circle over to the child ‘Class’ of your choice.
4. When the child 'Class' box highlights green, release the left mouse button over the 'Composition' section to add a decomposed by relationship.
5. Once added to the diagram, the new relationship should appear as a filled diamond shape and directional arrow from the parent to the child 'Class' construct.
6. Click the 'Save' button located on the toolbar to persist your changes to your project’s database.