Efficient Heuristics for Solving Order Picking Problem in a Multiple-Level Warehouse

• Main Authors: Pin-Hua Chen, 陳品樺
• Other Authors: Shine-Der Lee
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/95600098034626632149

碩士 === 國立成功大學 === 工業與資訊管理學系碩博士班 === 96 === We consider the order picking problem in a multiple-level warehouse, where a picker traverses through different levels and different aisles to pick an order with multiple items. In recent years, this multi-floor order picking system has become very popular in metropolitan areas where the cost to erect traditional single floor warehouse is prohibited, due to land restriction or other constraints. In this order picking system, the multiple-level warehouse layout is assumed known beforehand. Each floor includes multiple aisles with equal length and width. Items to be picked are stored with dedicated storage policy. Vertical transfer lifts are used to transport the picker from one floor to another. A picking tour is a specification of the sequence in which items in the specific order will be picked. For the specific order, the picker leaves the I/O point on the first floor, and traverses from one storage area to another between aisles and levels to pick the items, and finally returns to the I/O station. Due to the computational complexity, two efficient heuristics are developed in this thesis. The nearest item heuristic is a greedy procedure where the nearest item to the picker’s current position is selected. The minimum within-aisle picking cost procedure is a decomposition approach that finds the minimal within-aisle traversal cost one by one. Numerical experiments have shown that the first algorithm gives better solution quality when the number of items to be picked or the number of levels is small. When the number of items to be picked is large, the second algorithm gives better solution quality.