A manufacturing machine processing two product types arriving at constant rate and setup times involved is considered in this study. An optimal process cycle is derived with respect to minimal weighted time averaged work in process (wip) level. In addition, a feedback law is proposed that steers the system to this optimal process cycle from arbitrary start point. The analysis has been done for both unbounded and bounded buffer capacity. Although the analysis is done for continuous models, the feedback law has been implemented successfully in a discrete event simulation.