A generalized design and performance analysis model for end-of-aisle order-picking systems

In this paper we present an analytical design algorithm to determine the near-minimum number of pickers required in an end-of-aisle order-picking operation based on a miniload automated storage/retrieval system. The algorithm is based on an approximate analytical model we developed to estimate the expected picker utilization (and the storage/retrieval machine utilization) for general system configurations with two or more pick positions per aisle and/or two or more aisles per picker. For systems with two pick positions, we also investigate the possibility of improving the picker utilization by sequencing container retrievals within each order.