Warehouse Design and Management: a simulative approach to minimize the distance travelled by pickers

Abstract

In this work, we use a simulation approach to optimize the picking policy of a warehouse, with the aim to minimize the distance travelled by a picker, and thus to reduce the throughput time. The analysis was performed considering a traditional warehouse used for both storing and picking activities, with double-sided racks and a storage capacity of 1,200 pallets. We generated 50 different warehouse configurations by modifying the values of two input parameters (warehouse shape factor and location of the input-output depot) and adopting 4 different routing policy for each layout. Then we generated 10,000 different picking list of each scenario to gain statistical significance. The simulation results were recorded in a structured database and analyzed to determine the conditions that allowed for the minimization of the travel distance. The data analysis allowed also to evaluate the impact of the input parameters, both hardware (geometrical features) and software (management policies), on the distance covered by the picker and derive some managerial insights. One interesting result, referring to the combination of location of the picking input-output depot with a specific routing policy and a defined range of warehouse shape factors, is presented and discussed in greater detail. Finally, we suggest possible future research activities, including the analysis of different order sizes and rotation indexes.