揀貨作業是物流中心內耗用資源最多的作業活動之一，因此過去的研究無不致力於提升揀貨作業的效率。傳統上評估揀貨作業績效是以揀貨距離或揀貨行走時間為標準，其改善活動也是以如何縮短揀貨距離或揀貨行走時間最小化為首要目標。但實務上，多位揀貨員同時進行揀貨作業過程中常會發生的等待或阻塞，揀貨時間必然受到影響，故縮短揀貨距離或揀貨時間最小化，並不一定能得到最佳的揀貨績效。因此本論文提出以訂單完成率(throughput rate)為績效衡量指標來評估揀貨作業績效之分析架構，不同過去的研究是著重在揀貨距離的分析架構。本研究導入等候網路的觀念，建構以訂單完成率之數學分析模型，並且提供求解訂單完成率(throughput rate)的方法。利用相同參數建構模擬揀貨作業環境，模擬系統所得到訂單完成率與數學模型計算訂單完成率差異很小，因此證明本研究提出的數學分析模型具備良好估計能力。再進一步由訂單完成率的數學模型，探討訂單完成率與通道服務率之關係，發展新的啟發式儲位指派法則。本研究提出的儲位指派法則可經由設定通道之間服務率比例來進行品項指派，使得揀貨作業之訂單完成率最大化。
本論文旨在針對多揀貨員之人工揀貨作業下，提出績效評估數學模型及提昇揀貨績效之啟發式儲位指派法。第一章說明研究動機與目的。第二章相關文獻探討。第三章探討本研究倉儲環境及分析揀貨作業問題。第四章導入等候觀念，發展訂單完成率數學模型，並且求解訂單完成率(throughput rate)。接著發展啟發式儲位指派法。第五章運用3D模擬技術驗證揀貨作業之數學分析模型及啟發式儲位指派法之比較。第六章總結並說明未來發展方向。

This study investigates an order picking system involving multiple pickers in a warehouse. Travel distance or travel time has usually been employed to measure order-picking efficiency, since most previous studies assumed an order picking system only undertakes single picker operations. However, multiple pickers frequently work in the same area concurrently in an actual warehouse system and congestion inevitably takes place and the traditional travel distance or travel time might not be a proper measure for the system efficiency. Consequently, this study proposes a throughput model for the determination of the picking operation performance for such multiple-picker environment to consider a trade-off between the picking distance and the blocking-caused delay for the storage assignment. The proposed model is first validated by a simulation experiment and then used to compare the throughput of the warehouse under two popular storage assignment strategies with different demand distributions of stock keep units in the order picking system.
The study developed a storage assignment heuristic. The objective of heuristic is to maximize throughput rate of order picking system. The study compares the throughput rare for different storage assignment policies and demand skewness. The results show that the heuristic policy is better than another storage assignment policy.

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