This paper considers a flexible manufacturing system consisting of one unlimited central buffer and n workstations each having a limited local buffer. The in-process inventory is centralized through the central buffer. General independent random processing times as assumed at each station. The system is reviewed periodically. The paper addresses the routeing control problem, where the routeings of jobs from the central buffer to each station are to be determined periodically to minimize the in-process inventory costs. A dynamic programming model is developed for the determination of the optimal routeings. The computational formulae are derived, and a solution approach is established. The computational results for a real flexible manufacturing system are reported.