Waveless picking : managing the system and making the case for adoption and change

Abstract

Wave-based picking systems have been used as the standard for warehouse order fulfillment for many years. Waveless picking has emerged in recent years as an alternative pick scheduling system, with proponents touting the productivity and throughput gains within such a system. This paper analyzes in more depth the differences between these two types of systems, and offers insight into the comparative advantages and disadvantages of each. While a select few pieces of literature perform some analyses of wave vs. waveless picking, this paper uses a case-study of a waveless picking system in an Amazon.com fulfillment center as a model for how to manage a waveless system once it has been adopted. Optimization methods for decreasing chute-dwell time and increasing throughput by utilizing tote prioritization are also performed using discrete-simulation modeling. The analysis concludes that managing waveless picking warehouse flow by controlling the allowable quantity of partially picked orders to match downstream chute capacity can lead to reduced control over cycle times and customer experience. Suggestions are also made on possible future research for how to optimally implement a cycle-time controlled system.