反應全球運籌與動態需求之供應鏈與航空貨運網路設計

Abstract

廠商營運已從區域性的競爭轉變為全球化運籌的國際競爭。在全球運籌以及 多變的環境中，廠商如何依據未來景氣變動、產業結構變化、整合位於不同經濟 區域的上下游，進行零組件採購、物流服務運送等規劃，以求降低成本，實為廠 商最根本之基礎規劃與極為重要的議題。另外，為使物料、零組件、最終產品等 能在最短時間運至世界各地，廠商常依賴運輸速度快的航空貨運，使得航空運輸 需求增加。全球產業結構與各區專業分工逐年動態變化且密切影響航空運輸的需 求，航空貨運業者在進行運量預測時若能考量上述因素，藉以分析總體與個別航 線航空貨運量之循環變化，並以供需互動角度考量航空貨運供給因素對航空貨運 業者成本與需求量的影響，則航空貨運公司所規劃貨運網路與機隊規劃將能為廠 商與航空公司兩造均帶來成本效益。本研究擬構建一系列模式探討上述議題。 本研究嘗試應用網路設計模式、非線性混合整數規劃模式、互動式協商模 式、個體選擇模式與運量預測模式，進行一系列因應產業景氣循環、需求動態變 化以及上下游不同區位下之廠商之供應商選擇與零組件採購規劃、產品服務週期 規劃與航空貨運運量預測、航線費率和班機頻次規劃。本研究分為三年期研究計 畫。第一年期計畫擬針對零組件採購課題，首先以供應鍊網路設計模式為基礎， 藉由產品與零組件數量關係分析產品需求量對零組件需求量與採購決策的影 響，並納入生產據點與供應商地理區位分佈對供應商選擇的影響，構建供應商選 擇與零組件採購數學規劃模式，繼而透過可靠度評估模式，評估不可靠的供應狀 況，構建因應需求變動下之零組件採購網路調整模式。進一步，整合供應商零組 件供給模式與零組件採購網路調整模式，進行規劃求解之配套，透過廠商與供應 商個別規劃目標之間的權衡取捨，與兩造決策者就規劃目標間之相互協商互動， 得到協議下因應需求變動之最適供應商選擇與零組件採購量。第二年期計畫擬針 對產品配送課題，於供給面，以解析性方法構建顧客服務週期規劃下之單位產品 平均供給成本函數；於需求面，分析服務週期規劃對不同顧客選擇目標廠商意願 的影響，繼而，考量顧客需求依時間、空間分佈特性，總計研究期間內廠商產品 總需求量；進一步，以最大化廠商利潤為目標，考量供需互動、生產規模經濟與 運輸流量彙集經濟特性以及滿足各生產據點產能限制，構建差異化服務週期策略 數學規劃模式。第三年期計畫擬以航空貨運業為對象，於需求面，探討不同產業 各廠商對選擇以航空運輸運送貨物的因素以及選擇機率，繼而，透過經濟景氣循 環與產業結構動態變化分析，總計研究範圍內航空貨運需求量。另於供給面，以 解析性方法構建航空貨運業者供給成本函數，進一步，以航空貨運業者利潤最大 化為目標，考量供需互動下，求解各航線最適費率、班機頻次等決策。最後，本研究擬針對特定高科技產品廠商與航空貨運業者進行範例分析，以 驗證本研究不同年期所構建的模式在實際應用上的可行性與模式發展之潛力。本 研究在學術貢獻上可補過去文獻之不足，亦期能提供相關問題之其他學術研究之 參考。而在實務上，可提供廠商與航空貨運業者於全球運籌與動態需求下之供應 鍊與航空貨運網路設計決策，及研擬相關營運規劃及行銷策略之參考。

The challenge of a firm』s operation has been changed from regional competition to global competition. Under global logistics and dynamic economic environment, how to design procurement network and plan product delivery service strategy to effectively integrate suppliers and customers in geographical regions around the world has become an important issue for a high-tech product firm to achieve cost effective. In addition, air cargo demand has been dramatically increased due to its speed and convenience for delivering high-tech products. The growth of air cargo demand depends on the specialization and evolution of industrial structures all over the world. In other words, only if a model for predicting air cargo demand incorporates the influences of world trade due to above influences can fully account for the dynamic aspects of demand changes. Moreover, the decisions on airfare, flight frequency and aircraft type affect the cost and quality of air cargo services. A profit-maximizing air cargo carrier must investigate the impacts of the dynamic environment on air cargo demand and trade-off between the cost of providing service and the revenue generated by the service, when determining the airfare, flight frequency and aircraft type on its network. The proposed study attempts to explore above issues by formulating a series of models. This study attempts to apply network design models, non-linear mixed integer programming (MIP) models, interactive programming techniques, disaggregate choice and demand forecast models to develop a series of models on analyzing high-tech firms』 decisions, such as suppliers』 selection, key-component procurement size, product delivery strategies and air cargo carriers』 network design, in response to dynamic economic environment and global logistics. The three-year study includes three related topics. In the first year, this study formulates a high-tech firms』 optimal suppliers selection and procurement size programming model by considering the customer demand, locations of suppliers and plants as well as key-component discount and prices offered by various suppliers. Then, this study devises a reliability evaluation method for assessing how well the results of a procurement strategy will work under future possible demand fluctuations; and then proposes a fine-tuning method for redesigning the procurement network in response to unreliable supply situations. Furthermore, this study formulates a key-component supply model and presents an interactive supplier selection, price and procurement size procedure to facilitate bargaining interactions necessitated by supplier-manufacturing firm partnership agreements. In the second year, this study attempts to optimize a delivery service strategy for high-tech product firms by considering dynamic demand, demand-supply interaction, and production and shipping economies. First, this study employs the analytical method to formulate the supply cost function by considering the time-dependent demand of various customers in different regions. Then, this study formulates and incorporates disaggregate choice models to estimate customer demand for firm』s product. Furthermore, this study develops a MIP model for determining the optimal delivery service cycles for customers in different regions and the assignment of plants to customers, taking into account demand-supply interactions. In the third year, this study not only investigates the relationship between air cargo demand and world trade due to the specialization and evolution of industrial structure around the world but also proposes an airfare, flight frequency and aircraft type programming model for airline』s cargo network by considering close demand-supply interaction. This study formulates a disaggregate choice model to analyze the impacts of product values, distance as well as supply attributes, such as airfare and flight frequency on the optimal shipping mode choice. The air cargo demand is estimated by aggregating individual firm』s choice based on the probability distribution of the value of products, which are made in different industries. Then, this study formulates a mathematical programming model to determine flight frequencies and basic airfares on individual routes of an air cargo network with demand-supply interactions by maximizing the carrier』s total profit. Finally, a series of case studies about the selected high-tech product firms and air cargo carrier will be provided to illustrate the results and the application of the developed models. Consequently, the expected results of the developed models can provide basis on studies regarding procurement decisions, product delivery strategy and air cargo network design. Furthermore, the results may shed light on high-tech product firms and air cargo carriers regarding their decision-making on key-component procuring, product delivery strategy, marketing and operating strategies under global logistics and dynamic economic environment.