A method is provided of selecting operating parameters for an aromatization process having at least penultimate and final stages, each containing a respective catalyst, for optimum aromatic barrel per calendar day (AB/CD) production of product having a selected RON and/or over a particular run length. The catalyst lives are determined at constant LHSV for the penultimate and final stage catalysts for a given feed RON to each stage as a function of the change in RON from that of the feed to that of the C.sub.5+ effluent from the respective stage. The penultimate stage C.sub.5+ effluent RON is selected to be such that the lives of the catalysts in each stage are substantially equal. Preferably the yield of C.sub.5+ effluent from each stage and the life of the catalyst used in each stage is determined as a function of the pressure of that stage. The operating pressures of the stages are then selected to be within about 30% of that which gives the highest AB/CD.