| Second, we address the replenishment of the piece picking area in a warehouse. The productivity of broken-case picking operations can be increased by splitting an SKU inventory in a forward area (piece picking) and a reserve area (storage), although, on the other hand, this requires regular replenishments from one area to the other. The forward-reserve problem (FRP) is used to decide which products and in what quantities are to be stored in the forward area, so that the total cost of order picking and replenishment is minimized. A variant of the VRP and the TSP are used to batch picking orders and optimize picking paths. The possibility of stockouts in the picking racks is not considered, although they occur in industrial practice. We propose a procedure for scheduling forward area replenishment orders aiming at the reduction of stockout probability. |
