Picking-replenishment synchronization for robotic forward-reserve warehouses

Forward-reserve strategy is commonly applied when processing a large number of small orders. This paper considers robotic forward-reserve warehouses, where pick locations are brought to workers by mobile robots in the forward area. We treat the critical problem of unsatisfactory efficiency in the robotic forward area. A picking-replenishment synchronization mechanism (PRSM) is thereby proposed, which optimally attains a balance between replenishment efforts and picking efficiency. The resulting problem is formulated and solved by a tailored variable neighborhood search procedure integrated with a divide-and-conquer paradigm. Numerical results reveal remarkable benefits of PRSM over the conventional random schemes under different scenarios.