Current rule base maintenance is wasting refinement and inference performance. There are only few maintenance concepts, which enjoy both (1) formal rule refinement and (2) utilizing topical knowledge provided by experts within the refinement process. The current state of the art in rule base validation and refinement reveals that there is no generic validation interface and no optimal rule trace refinement. This paper characterizes two different retranslation approaches for reduced rule bases and proposes a two-step validation process, which combines a case-based approach with a rule trace validation approach.