全溫層物流設施與作業規劃研究

Abstract

近年來，隨著宅配服務與電子商務之興起，配送物品朝著多樣少量與多溫層的方向發展，該趨勢亦使物流業者對多溫共配之相關課題日益重視。除在運送貨物品質之控管問題外，全溫層物流於場站使用之技術類型、車輛型式、車輛大小、等中期設施規劃問題以及如何提升短期作業效率問題都是未來發展的重要課題之ㄧ。有關全溫層物流的文獻較為少見，其中以全溫層物流新技術的開發與應用佔大部分。目前常見之配送方式大致可分為單溫配送與多溫共配兩種，在貨運規劃相關文獻中，鮮少將各種物流技術與多溫層貨物同時納入考量與探討；另在提升短期作業效率相關研究中亦鮮少將儲位指派視為短期作業規劃問題，而儲位指派良窳卻可能是提升物流中心短期作業效率之重要關鍵。 本研究將針對中期設施規劃與短期作業規劃構建兩種模式探討全溫層物流在陸運上之營運規劃相關議題。中期設施規劃部分是假設場站區位與需求為已知條件下，以業者的角度，追求運輸成本與貨物處理成本所加總之總運送成本最小化為目標。運輸成本包含運具成本與場站成本，兩者均包含期初投資之固定成本與變動成本，並在滿足顧客需求下，求解業者所需投資之場站技術、車輛型式與大小等設施，以及在該設施投資下所搭配之最適貨物處理量、服務頻次與車輛路徑等。短期作業規劃部分則是假設場站貨物處理量適合採用傳統多車配送技術，並分別使用冷凍、冷藏與常溫之自動倉儲系統情境下，針對低溫食品特性建構兩階段動態儲位指派模式。第一階段指派先分析各種低溫食品隨著時間而快速腐敗之特性，而將越接近期限的低溫食品越先指派至中下游，且將過期之低溫食品移出儲位，進而瞭解空儲位分佈狀況；第二階段指派則考慮低溫食品具有需求量依時變動之特性，結合動態灰預測與第一階段指派之結果，將低溫食品指派至空儲位並使後續作業有效率的進行。 最後，本研究進行範例分析，在中期設施規劃部分，發現抽換式蓄冷保溫箱多溫共配技術適合需求量較小之場站、場站分布密集與營運範圍小之網路型態，亦較能因應外在環境變動趨勢。而傳統多車配送技術則因為具有規模經濟特性適合需求量較大之營運網路。在短期作業規劃部分，本研究結果證明所構建之模式，可使相同之低溫食品指派至相近的儲位以及使較接近出口/裝卸站之儲位的周轉率提昇，進而加強自動倉儲系統的揀貨效率；並可隨著低溫食品依時變動的特性，隨時改變儲位配置情形，使之更容易達到儲位高利用率之目標。以上結果可驗證本研究所構建的模式在實際應用上的可行性與模式發展之潛力。

The continued growth of demand on multi-temperature products and wide spread of timely customer demand has greatly contributed to the challenge of logistics carriers. Under the MTJD system and various deterioration of products, how to design a service strategy to serve consumers with distinct demand has become an important issue for a MTJD carrier to achieve cost effective while maintain the maximized customer satisfaction. In practice, the categories of the multi-temperature distribution system include single-temperature distribution and MTJD. Some studies have analyzed the problems on distributing regular and/or specific-temperature products but few of them focused on multi-temperature products. Past studies have largely discussed the development of techniques applied in the MTJD system. Moreover, in the field of physical distribution problems, the MTJD problem combined with techniques employed are seldom discussed. Furthermore, storage assignment could be considered as one of the most prominent factors in improving short-term operational efficiency of the distribution center, but storage assignment is often neglected in the short-term operational efficiency planning. This study attempts to solve the issues related to multi-temperature distribution on land and is separated into two sections: mid-term facilities planning, and short-term operational planning. Assuming that terminal locations and demands are known, mid-term facilities planning aims to minimize the total delivery cost, tries to find the most suitable multi-temperature joint distribution system techniques, product handling quantity, vehicle type, vehicle size, vehicle route, and delivery frequency, and at the same time without sacrificing customer satisfaction. Distribution cost includes product handling and transportation costs. Transportation cost, included in the fixed and variable costs during the initial investment process can further break down into vehicle cost and terminal cost. Under the automated storage and retrieval system and with the condition that terminals use traditional single-temperature distribution, short-term operational planning constructs two stages of dynamic storage assignment methods for refrigerated food. The first stage assignment assigns storage food to retailers and takes the overdue food out by analyzing the perishable properties of food according to its expiration time. The layout of occupied and vacant space will be obtained by this assignment. The second stage assignment combines the demand forecast results of various refrigerated items using dynamic grey predictions and the results of the first stage assignment. And continuously assigns different food items to empty space according to their forecasted demands efficiently. Lastly, this study conducts analysis on series of cases studies and finds that in mid-term facilities planning, results indicate the model is feasible for facilities planning for MTJD. The replaceable cold accumulation and insulation box MTJD technique is suitable for operation networks with densely distributed terminals and uneven temporal and/or spatial demand distribution. For short-term operational planning, a simulated case study about practical automated storage and retrieval system is provided to demonstrate the feasibility and the results of applying the proposed model. The results show that the model developed in this study can result in higher space utilization as compared with those conventional models.