The effect of warehouse cross aisles on order picking efficiency

This paper investigates the effects of adding cross aisles to the layout of an order consolidation warehouse, with respect to order picking efficiency . Intuitively, cross aisles provide greater flexibility in the routing of o rder pickers, thus providing shorter order picking travel distances. Howeve r, this effect may be negated when the number of cross aisles becomes exces sive, as the cross aisles themselves must be traversed in order to reach th e required items. A shortest path pick sequencing model is developed which allows for any number of cross aisles in the warehouse. The optimal routing is computed for a large number of randomly generated picking requests, ove r a variety of warehouse layout and order picking parameters. The results a re used to characterize the optimal number of warehouse cross aisles, as we ll as the conditions under which cross aisles generate the greatest benefit .