Reducing workload imbalance in parallel zone order picking systems

Abstract

To stay competitive and preserve high service levels for their customers, the focus of warehouses in today’s supply chain is on timely and faster delivery of smaller and more frequent orders. To keep up with competitors, companies accept late orders from customers, which results in additional pressure for order picking operations. Specifically, more orders need to be picked and sorted in shorter and more flexible time windows, which often results in workload peaks during the day. The objective of this study is to balance the workload across the day in parallel zone order picking systems. A real-life case-study demonstrates the value of balancing the workload for European order lines in a large international warehouse system located in Belgium, engaged in the distribution of spare parts. Solving the operational workload imbalance problem results in a more stable order picking process and overall productivity improvements for the total warehouse operations.