Data Management Capabilities > Managing Part Structures > Windchill Options and Variants Capabilities > Developing Advanced Selection Logic for Configurable Modules > Basic Steps for Defining Advanced Selection > Adding a Constraint
Adding a Constraint
Adding a constraint allows you to specify a condition for a configurable module. A constraint can be simple, consisting of only one part, or can be more complex, consisting of multiple parts.
To add a constraint:
1. In the Part Structure Browser, select the configurable module for which you want to add a constraint.
2. Click the Constraints tab.
3. From the tool bar, select Actions > New, and select any of the following constraint types:
Case Table
External Application
Or you can click the corresponding icons on the tool bar.
4. Define the constraint in the corresponding window. Specify the name and description for the selected constraint type.
5. (Optional) Enter any identifying alert text. The Alert shows this message if the constraint is violated. A violation of the constraint produces an automatically generated message, which lists the expression that defines the constraint when no alert is specified. For an Expression constraint type, the expression can be entered directly in the Expression field or by using the selections available in the Expression Editor to form the expression.
You can also add constraints within the same configurable module using copy and paste. This functionality is not available for copying constraints from one configurable module to another.
For the Case Table constraint type, select the parameters to be used in the case table. For more information, see Selecting Case Table Parameters.