SEQUENCING METHODS FOR AUTOMATED STORAGE AND RETRIEVAL-SYSTEMS WITH DEDICATED STORAGE

In this paper, we study the effect of sequencing storage and retrieval requests on the performance of automated storage and retrieval system s (AS/RS) where a storage request is assigned a predetermined storage location. By exploiting this unique operating characteristic, we prese nt several optimum and heuristic sequencing methods under static and d ynamic approaches. Applications of such sequencing methods include uni t-load AS/RS with dedicated storage, miniload AS/RS, and potentially u nit-load AS/RS with randomized storage. We find that the sequencing me thods can significantly reduce travel time by a storage and retrieval machine, thereby, increasing throughput, and that the dynamic heuristi c method is simple and fast, yet considerably outperforms the others. (C) 1997 Elsevier Science Ltd.