A survey on single crane scheduling in automated storage/retrieval systems

This paper addresses the scheduling of a single storage/retrieval machine (or crane) in automated storage/retrieval systems (ASRSs). A novel classification scheme is presented for precisely defining different versions of the crane scheduling problem, when varying the layout of the ASRS, the characteristics of the storage and retrieval requests, and the objective function. This classification scheme is then applied for presenting different (known and novel) exact algorithms and complexity proofs for a variety of crane scheduling problems, for reviewing the literature, and for identifying future research needs. (C) 2016 Elsevier B.V. All rights reserved.