Sequencing and routing in a large warehouse with high degree of product rotation

Abstract The paper deals with a sequencing and routing problem originated by real-world application context. consists in defining the best sequence of locations to visit within warehouse for storage and/or retrieval given set items during specified time horizon, where storage/retrieval location an item is given. Picking put-away are simultaneously addressed, also considering some specific requirements layout design operating policies which typical kind warehouses under study. Specifically, considered policy prescribes that must be replenished or emptied one at following order precedence. Moreover, two fleet vehicles used perform retrieving storing operations, whose restricted disjoint areas warehouse. We model as constrained multicommodity flow on space-time network, we propose Mixed-Integer Linear Programming formulations, primary goal minimize traveled horizon. Since large-size realistic instances hardly solvable limit commonly imposed context, matheuristic approach based horizon decomposition proposed. Finally, provide extensive experimental analysis aiming identifying suitable parameter settings proposed approach, testing particularly hard scenarios. computational experiments show efficacy efficiency approach.