發展連續性概似模型以解決在運輸成本具折扣下之多階層配銷系統設計與存貨補充策略;Continuous Approximation Models for Solving Multi-Echelon Distribution System Design and Inventory Replenishment Policy under Transportation Cost Discounts

NCUIR > School of Management at National Central University > Graduate Institute of Industrial Management > Research Project > Item 987654321/57493

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/57493

Title:	發展連續性概似模型以解決在運輸成本具折扣下之多階層配銷系統設計與存貨補充策略;Continuous Approximation Models for Solving Multi-Echelon Distribution System Design and Inventory Replenishment Policy under Transportation Cost Discounts
Authors:	沈國基
Contributors:	中央大學工業管理研究所
Keywords:	管理科學
Date:	2008-09-01
Issue Date:	2012-10-01 15:36:24 (UTC+8)
Publisher:	行政院國家科學委員會
Abstract:	離散式模型提供管理者最佳解，但資料與電腦需求卻隨著模型愈趨近實務而大幅增加。資料的可靠度與模型的精確度有可能如此而遞減。連續性概似模型基於少量資料的需求與接近最佳解的特性可以補救以上的缺失 (Dasci and Verter, 2001)。連續性概似模型搭配最佳化的方法的使用可以是一個強大的求解問題工具 (Langevin, 1996)。因此在本研究我們將利用連續性概似模型以解決多階層配銷系統設計與存貨補充策略。而將會面臨的挑戰即為如何以連續性概似模型趨近各系統成本以及如何發展非線性最佳化技術來求解問題。聯合多品項的補貨策略已廣泛被應用在實務上。較大宗商品的運送即可能因為運輸經濟規模而獲取一些運輸成本折扣。在這研究中我們將考慮在運輸成本具折扣下之整合性的設廠位置與存貨分配問題。主要的問題決策包含區域性配銷中心的設廠位置，如何分派零售商給區域性配銷中心以及這些配銷中心的存貨補充策略，其目標為最小化整個系統成本。而此問題卻因為多個變數、折扣的形式以及在實務上大量的資料而變的非常難解。直接去處理此多品項的問題並不容易。取而代之，我們會先考慮單品項的問題。接著再延伸此單品項模型去考慮多品項問題。因此我們計劃以兩年的時間完成此研究，第一年針對單品項問題而第二年則進一步考慮多品項問題。在第一年，我們將考慮在運輸成本具數量折扣下的單品項多階層配銷系統的設計與存貨補充策略。在許多實務的狀況，客戶的訂單可能以單位承載方式透過航空或地面運輸來運送。此時比較大量商品的運送即可能因為運輸經濟規模而獲取一些運輸成本折扣。我們將建構一個包含設施成本、運輸成本和存貨成本的總系統成本數學模型。連續性概似模型將被提出以求解上述問題。我們將搭配使用非線性規劃相關技術以發展求解的方法。在第二年，我們將延伸單一品項模型去考慮在多品項多階層供應鏈中當運輸成本折扣與運輸商品總重量成正向關係之多階層配銷系統設計與多品項配送問題。我們將延伸單一品項模型建構一個針對多品項模型的全系統成本模型。我們將使用連續性概似模型並搭配非線性求解方法以解決問題。本研究主要的貢獻之ㄧ即在於當離散式資料無法被建構成連續性方程式時，我們將嘗試以連續性概似模型技術解決以解決這問題。透過數值分析，我們將探討系統參數對系統決策與行為的影響。完整的數值分析將被用以驗證模型結果之正確性與實際現象之吻合度並提出一些結論。我們期望此研究成果可提供給管理者於決策與經營上之有利參考與依據。 ; Discrete models provide managers with optimal solutions but data and computational requirements increase tremendously as models become more realistic. Also, data reliability and hence model accuracy decrease. Continuous approximation could be a remedy to these weaknesses due to lesser data requirements and closed or near-closed form solutions (Dasci and Verter, 2001). Also, the use of continuous approximation models in conjunction with optimization method has been proved to be a powerful tool for problem solving (Langevin, 1996). Therefore in this study, we will utilize continuous approximation models to solve the multi-echelon distribution systems design and inventory replenishment policy. The challenges will be how to use continuous approximation model to estimate each system cost and how to develop non-linear optimization approach to solve the problem. Joint multi-item replenishment strategies are already widely applied in the real world. Discounts for heavier freight may be provided so as to enable transportation economies of scale. In this study we will consider an integrated facility location and inventory allocation problem with transportation cost discounts. The key decisions are where to locate the regional distribution centers (RDCs), how to assign retail stores to RDCs and how much inventory to hold at the different locations such that the total network cost is minimized. This is a very hard problem due to the multiple variables, discount form and large size data in reality. It is not easy to deal with the multi-item problem directly. Instead, we should consider the single-item problem first. Then we will extend the single-item model to consider the situation of multi items. Therefore, we plan to spend two years to complete this study, while the first year is used for developing the the single-item model and the second year is for the multi-item model. In the first year, we will consider a single-item multi-echelon distribution system design and inventory replenishment policy under the freight cost involving quantity discounts offered due to economies of scale. In many practical situations, the customer’s order may be delivered in unit loads via air or surface transportation etc. Discounts for larger quantities of freight may occur due to transportation economies of scale, in terms of the number of unit loads delivered. We will construct a mathematical model to express the total system cost which includes facility cost, transportations and inventory cost. A continuous approximation model will be provided for solving the problem. The solution techniques will be developed using the theory of nonlinear programming. In the second year, we will extend the single-item model to consider the situation when price freight–transport discounts that are positively related to the weight of cargo transported in a multi-item multi-echelon supply chain. We will extend the single-item model to determine the total system cost for multi-item model. We will use continuous approximation model and develop a solution procedure for solving the problem. A main contribution of this work will be lying in developing a refined continuous approximation modeling technique when the discrete data cannot be modeled by a continuous function. Through the computation analyses, we will discuss the influences of system parameters on decisions and behaviors of the system. We hope to conclude with computation analyses that lead to a variety of management insights. These results should be a useful reference for managerial decisions and administrations. ; 研究期間 9708 ~ 9807
Relation:	財團法人國家實驗研究院科技政策研究與資訊中心
Appears in Collections:	[Graduate Institute of Industrial Management] Research Project

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