Systems and methods of dehydrogenating a hydrocarbon in a fixed bed dehydrogenation unit. A method for dehydrogenating a hydrocarbon is applied to a fixed bed reactor. The hydrocarbon flows to a fixed bed reactor to be dehydrogenated in presence of a catalyst in the fixed bed reactor. The catalyst in the fixed bed reactor is then regenerated. The period for dehydrogenation, the period for catalyst regeneration and the period for total slack time are controlled such that total slack time is less than both half of the period for dehydrogenation and half of the period for regeneration. One of the advantages of the process comes from optimization of the slack time, thereby increasing the catalyst utilization rate and number of reactors concurrently online.