The Constrain relationship is a PTC proprietary relationship that is available only when the MBRE Profile has been added to a model.
You can create Constrain relationships through a Use Case Diagram, MBRE Traceability Diagram or Modeler pane.
When you add a Constrain relationship to a Use Case, Modeler applies the «UseCaseRelated» stereotype to that Use Case. On the UseCaseRelated tab of a Use Case's Property Pages, the constrainedBy and constrains tag definitions show how the Use Case is linked to other Use Cases through Constrain relationships.
To create a constrain relationship through a use case diagram
1. If you have not done so already, add the Use Cases you want to link to the Use Case Diagram.
2. On the diagram's toolbar, click the Constrain button.
3. Click the constraining Use Case, and then click the constrained Use Case.
4. Type the name of the Constrain relationship, and then press the Enter key.
To create a constrain relationship through a Modeler pane
1. Right-click the constraining Use Case, point to Links, point to Traceability, and then click Constrains.
2. For each Use Case that is constrained by the item you right-clicked:
a. In the Link Items browser, select the Use Case.
b. Click the Link button.
3. Click OK.
Alternatively,
1. Right-click the constraining the Use Case, and then click Links > Start Link.
2. For each Use Case that is constrained by the Use Case you right-clicked:
a. Right-click the Use Case, and then click Links > End Link.
b. From the Relationship list, select Constrains, and then click OK.
To create a constrain relationship through an MBRE traceability diagram
1. If you have not done so already, add the Use Cases you want to link to the MBRE Traceability Diagram.
How?
2. On the diagram's toolbar, click the Constrain button.
3. Click the constraining Use Case, and then click the constrained Use Case.
4. Type the name of the Constrain relationship, and then press the Enter key.
Constrain button.