As applications and systems have grown complex, so has the complexity of maintaining valid configurations for them. Usually, policies are treated as {event, condition, action} rule sets and are used to maintain systems in valid configurations. In this paper, we use policies, defined as configuration constraints on object-oriented models of systems, to generate configurations that meet those policies. We describe Cauldron, a policy-based design tool for this purpose. The paper discusses the Cauldron language, and shows how various relationships present in objectoriented models are coded using the Common Information Model (CIM) as an example. We also discuss the implementation of Cauldron, specifically as it relates to the underlying theory that enables it to generate valid configurations. We have also used a partitionable system as a case study for validating Cauldron.