Scattered Storage: How to Distribute Stock Keeping Units All Around a Mixed-Shelves Warehouse

Scattered storage is a storage assignment strategy where single items are isolated and distributed all around the shelves of a warehouse. This way, the probability of always having some items per stock-keeping units close-by is increased, which is intended to reduce the unproductive walking time during order picking. Scattered storage is especially suited if each order line demands just a few items, so that it is mainly applied by business-to-consumer online retailers. This paper formulates a storage assignment problem supporting the scattered storage strategy. We provide and test suited solution procedures and investigate important managerial aspects, such as the frequency with which refilling the shelves should be executed.