On a selection and scheduling problem in automatic storage and retrieval warehouses

Abstract

Warehousing is one of the main components of the supply chain and its optimization is crucial to achieve global efficiency. Warehouse operations in- volve receiving, shipping, storing and order picking, among others, and the coordinated optimization of all these different operations is highly complex. This paper approaches a selection and scheduling real problem that arises in an automatic storage/retrieval warehouse system involving the scheduling of forklifts pickup operations. The objective is to minimize the total loading time of the vehicles performing transportation, while respecting their departure due dates. This complex problem is approached through a two-phase decomposi- tion method, combining both exact and heuristic procedures. The performance of the proposed solution method is evaluated through extensive computational results performed on several scenarios from a real case study built from data from a real mattress warehouse.