This paper investigates the performance of due-date assignment rules in a flexible manufacturing system (FMS) Although emphasis is placed on a comparison of due-date assignment rules, machine and automated guided vehicle (AGV) scheduling rules are also evaluated under various experimental conditions using an FMS simulation model. The mean job tardiness is the measure of performance by which the rules are compared. The sensitivity to AGV workload, buffer capacity, and processing time distribution is also investigated to assess the robustness of the due-date assignment rules. © 1995 Taylor & Francis Ltd.