Wave Release Strategies to Improve Service in Order Fulfillment Systems

Abstract

Distribution centers in the Department of Defense (DoD) have become critical components in getting supplies to the warfighter. In the case of repair parts and other essential items, they become a critical component of the operational availability of major weapons systems. In general, the more quickly the logistics system responds to requests, the higher the availability because total downtime is reduced through reduced mean logistics delay time. The desire to fulfill warfighters orders immediately, however, must be tempered by the need to provide service at a low cost, which means taking advantage of economies of scale in warehouse picking operations. To strike this balance, distribution centers in the DoD release orders in large batches called waves. Despite their ubiquity in military and commercial warehouse operations, there are no analytical models to determine the optimal number and timing of these waves, especially to maximize performance against deadline-oriented metrics such as Next Scheduled Departure, which is used at the Defense Logistics Agency. We address this deficiency by developing methodologies to determine the optimal number and timing of order releases in a distribution center.