A computer-implemented method and apparatus thereof for validating combinations of product features that are compliant with existing business rules relative to a modified business rule, where the modification includes an include and/or an exclude ZDD rule component. The method comprises obtaining combinations of features compliant with the existing business rules, processing the combinations against a representation of the rule components to determine validity against the modified business rule, and providing to a user an indication of validity of the combinations relative to the modification. The processing optionally comprises forming a representation of a record-by-feature array having rows corresponding to the combinations, ordering columns of the array according to one of the rule components, and testing validity of the rows of the array against the rule component. The features or combinations arc optionally read from a database, and optionally include a service.