Constraints
A constraint is a limitation imposed upon the functionality of a system. It has measurable and testable values. For more information about a Constraint, see Constraint (Dictionary Definition).
On constraint diagrams
Select the 
button on the Constraints Diagram tab to add a constraint to your diagram, or you can drag and drop a constraint from the dictionary.
button on the Constraints Diagram tab to add a constraint to your diagram, or you can drag and drop a constraint from the dictionary.When you have added a constraint, you can change it both via the diagram using the constraint Property pages or the context menu. With the Property pages you apply targets and values to your constraint.
On diagrams that are not constraint diagrams
Create or add Constraints to a diagram through the 
Constraint button. When you create a Constraint on a diagram, the Constraint is owned by the item that owns the diagram.
Constraint button. When you create a Constraint on a diagram, the Constraint is owned by the item that owns the diagram.On the diagram, you can apply a Constraint to an item through the 
Note Link button – link the item to the Constraint. Note that if you delete the Note Link from the diagram, the Constraint will remain applied to the item.
Note Link button – link the item to the Constraint. Note that if you delete the Note Link from the diagram, the Constraint will remain applied to the item.In a Modeler pane
You can create a Constraint from most item types by right-clicking the item, selecting > . When you create a Constraint from an item in this way, the Constraint is owned by the item. In addition, Modeler applies the Constraint to the owning item.