Plant PowerOps (PPO) [9] is a new ILOG product, based on business rules and optimization technology, dedicated to production planning and detailed scheduling for manufacturing. This paper describes how PPO integrates a rule based system with the optimization engines and the graphical user interface. The integration proposed is motivated by the need to allow business users to manage unexpected changes in their environment. It provides a flexible interface for configuring, maintaining and tuning the system and for managing optimization scenarios. The proposed approach is discussed via several use cases we encountered in practice in supply chain management. Nevertheless, we believe that most of the ideas described in this paper apply in almost any area of optimization application.