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

• This paper surveys crane scheduling in automated storage/retrieval systems.
• A novel classification scheme is presented.
• Two novel complexity results are presented.
• Future research needs are identified.

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.