Have you had an experience that you had deleted an association line from diagram but when you look into the [Association] tab of models, it’s still there.
The reason is simple, you just deleted its presentation from the diagram, not completely from the project.
In Astah there are two ways to delete models. Let me show you the difference. Let’s say you have two classes with an association between the two.
Removing its presentation
If you select [Delete from Diagram] from the association’s pop-up menu or hit [Delete] key, an association line will be deleted from the diagram.
But when you go to “Monitor” class’s property view, the association information still exists.
So this menu only deletes the presentation from diagram but the model itself still exists. Sometimes you may represent same model in several diagrams and hide its visibility from one depending on the purpose of the diagram. In that case choose [Delete from Diagram].
Removing ompletely from project
Selecting [Diagram from Model] from its pop-up menu or hit [Ctrl/Command + D] key will delete the association presentation from diagram and also from the project. So choose this way when you are sure that you want to delete this model completely from the diagram such as when you made a mistake creating this association..etc.
If you want to check our Astah’s shortcut key list, check out the page here.