Configuring Propagation Rules for Unbound Inherited Attributes in Complex Inheritance Models

The issue occurs within configuration models that rely on object-oriented type inheritance for rollups and service calculations. In complex inheritance models, child types inherit all quantity attributes from their parent type. If a child type does not explicitly bind or constrain an inherited attribute, the configuration engine treats it as "unbound." During propagation, the engine may automatically adjust these unbound attributes to negative numbers to satisfy modeling rules (e.g., rolling up an empty relation total to a negative value instead of stopping at zero). This creates inaccurate totals that break downstream logic, such as service attach rules. To prevent this behavior, modelers must manually constrain all unused, inherited quantity attributes to 0 in every child class.