Systems and methods are disclosed for managing the operation of a plant, such as a chemical plant or a petrochemical plant or a refinery, and more particularly for enhancing system performance of a catalyzed reaction system by, among other features, detecting catalyst deactivation and cycle length. Plants may include those that provide hydrocarbon cracking or other process units. A plant may include a reactor, a heater, a catalyst bed, a separator, and other equipment. The equipment may use catalyst to treat feed products to remove compounds and produce different products. Catalysts used in the various reactors in these processes become deactivated over time. Systems and methods are disclosed for extending catalyst life and thereby improving efficiency of the plant.