Manufacturing systems generally encompass processes that are discrete in time and space. Among the variety of real-time supervisory control techniques reported in the literature, controlled-automata-based discrete event system (DES) theory is one of the few with mathematical formalism. However, the control of even a moderately complex system using this theory may require a very large control strategy. To attempt to cope with this problem, a hybrid supervisory controller was developed that splits operations between a DES-theory-based supervisory controller and an alternate mechanism. The alternate mechanism reroutes part production in real time whenever a priori unmodeled events occur. This modified approach provides a significantly more efficient controller than could be attained using solely a DES-theory-based supervisory controller.