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Connector Constraints

A UML connector can have associated constraints placed on it. Constraints provide information on the rules and conditions under which a relationship operates. For example, it might be a pre-condition that a customer is of a certain type before an Association connector to an Account is allowed.

You can add the constraints using the 'Constraints' tab in either the connector 'Properties' dialog or the Properties window; the fields are the same.



Start > Application > Design > Properties > click on connector in a diagram > Constraints   (Properties window)

Click on connector in a diagram

Design > Element > Editors > Element > Properties Dialog   (connector 'Properties' dialog)

Keyboard Shortcuts

Ctrl+2 > click on connector in a diagram > Constraints     (Properties window)

Context Menu

Right-click on Connector | Properties > Constraints    (connector 'Properties' dialog)


Double-click on Connector > Constraints    (connector 'Properties' dialog)

Set constraints on a connector



See also


Type the name of the constraint.


Click on the drop-down arrow and select the appropriate type of the constraint (such as Pre-condition).


Type any explanatory notes you might require on the constraint. You can insert line breaks in the text by pressing Ctrl+Enter.


Click on this button to save the constraint definition.

The constraint is added to the 'Defined Constraints' list.


Click on this button to clear the dialog fields so that you can enter details of a new constraint.

Defined Constraints

Displays a list of the constraints defined for this connector.


Click on this button to delete a constraint you have selected in the 'Defined Constraints' list.

The constraint is immediately removed from the list.


  • Constraints on an Association connector can be added to further refine the model; constraints detail the business and operational rules for the model