You can delete connections that do not have any occurrences in models for specific objects.
Procedure
Click Properties. The Properties bar opens.
Select the occurrence of the relevant object in the model window.
Click the Relationships tab if it is not activated yet. The relationships of the selected object are listed.
Next to the name of a relationship that has no occurrences in a model (connection), click More > Delete.
If the connection no longer has any occurrences in any model, it is deleted. If it still has an occurrence in a model, a message is displayed and the connection is not deleted.