A bi-directional scheduling approach for job shops

In this paper, we propose a method for scheduling job shops that combines two distinct manufacturing/management philosophies, push systems and pull systems. A bi-directional heuristic algorithm is presented which simultaneously addresses the reduction of mean flowtime (i.e. a measure of work-in-process) and mean tardiness (i.e. a measure of customer service). The algorithm is applied to realistic manufacturing situations and its performance with respect to mean flowtime and mean tardiness is compared with the performance of traditional scheduling approaches. In addition, we demonstrate that schedules generated by the bi-directional scheduling algorithm have a better-balanced workload and are therefore more robust than traditional schedules.