This paper presents a simulation-based approach for designing a non-linear override control scheme to improve the performance of a local linear controller. The higher-level non-linear controller monitors the dynamic state of the system and calculates an override control action whenever the system is predicted to move outside an acceptable operating regime under the local controller. The design of the non-linear override controller is based on a cost-to-go function, which is constructed by using simulation or operation data. The cost-to-go function delineates the admissible region of state space within which the local controller is effective, thereby yielding a switching rule.