Go to: Models tab>select model under Model Name>Parameters>Edit
Parameter constraints allow you to customize each parameter. Depending on the type of rules applied, you can either select a range of values, individual values, or set up relationships for each External Parameter Name. Like external parameters, constraints are viewed by your web site's end-users. If you do not implement constraints, the end-user can select only the default value defined with the model.
Rules govern the way parameters interact with models that include design tables. However, not all rules allow you to use constraints. You can use constraints in combination with the following rules:
Basic Rules. With Basic Rules (the default setting), unequal numbers of elements exist for each parameter. The parameters are unrelated, and there is no invalid combination of values.
Hierarchical Rules. Hierarchical Rules allow complex relationships between parameters. Using hierarchical rules can reduce the data set in comparison to Design Table Rules, easing data entry and maintenance. Hierarchical Rules are appropriate for models that require the user to select parameters in a specific order. The XML interface returns only valid combinations of data, based on the selections made during the parameter selection process.
Constraints are not available with models using Design Table Rules, since the values in the design table define the rules. In the Design Table Rules mode, each row in the design table represents a valid combination of values. Each parameter has an equal number of values. The XML interface returns both valid and invalid values for each parameter. The Design Table Rules mode is appropriate in most cases, especially when the user chooses parameter values in random order.
The following constraints only apply to Basic Rules. Constraints include:
Assign a range of values, from Min Value to Max Value.
Within the value range, you can specify the increment value (Step By).
Save or modify the range and the increment value.
Select individual values to create a list of constraints.
Save as many values as required.
Add new values or delete any values that are obsolete.
Accept the default value for the parameter.
The parameter uses the value defined in the model.
General information: