Analysis of economic and ergonomic performance measures of different rack layouts in an order picking warehouse

Abstract

Manual order picking ranks among the most time- and cost-intensive activities in warehouses, and it has frequently been studied in the past. The aim of existing studies was to improve the operational efficiency of order picking processes mainly by developing planning models that help to reduce the time that is needed for order picking. As order picking is still performed manually with technical support in most warehouses, human workers play an important role for order picking performance. Although it is recognized that manual material handling activities in warehouses expose workers to a high risk of developing musculoskeletal disorders, integrated planning approaches that consider both economic and ergonomic objectives in order picking design are still rare. This paper contributes to closing this research gap by developing economic and ergonomic performance measures for the case where orders are picked from pallets, half-pallets and half-pallets equipped with a pull-out system. The comprehensive analysis of the different rack layouts shows that there are opportunities to replace the traditional pallet storage system by half-pallets with a pull-out system on the lower rank to improve both ergonomics and economic performance.