Restricting the Allowed Values Dynamically
Purpose
When you define a Class to class assignment, and a characteristic has different allowed values in the two classes, the allowed values are automatically restricted by the system.
The system always restricts the allowed values to the lowest common denominator. The restricted allowed values are always an intersection of the values assigned in the hierarchy and the values that are allowed in the class.
The principle of the lowest common denominator also applies to the attributes of the characteristic:
If the attributes of a characteristic are different in the two classes, because the characteristic has been overwritten (see Overwriting Characteristics ), the restricted attributes are also an intersection. For example, if interval values are allowed in class A but not in class B, then interval values are not allowed.
The following constellations are possible when restricting the allowed values of a characteristic.
The characteristic has the same allowed values in both classes. When you assign values to the characteristic, the allowed values are restricted for the subordinate class.
See Same Allowed Values (Example 1) .
The characteristic has different allowed values in the two classes. The allowed values in the subordinate class are restricted to an intersection of the values allowed in the class and the values assigned to the characteristic when you created the assignment to a superior class.