航空公司貨運網路航線頻次與機型規劃之研究

Abstract

航空貨運需求與航空公司貨運航線頻次、機型規劃、及航空公司間之競爭，存有密切的供需互動關係，故以系統化的觀點研究航空貨運網路有其必要性。本研究以國際航空公司為研究對象，航空貨運為研究範圍，分析航空公司在面臨競爭經營環境下，如何因應需求變動及其他競爭航空公司之競爭策略與競爭行為，以規劃航空貨運航線之最適營運頻次與機型。因此，本研究就多對多航空網路型態，考慮航空公司的經營環境、營運條件、競爭航空公司之競爭策略與競爭行為、及貨主託運貨物之特性，構建結合經濟理論與網路數學規劃之模式，分析上述考慮因素對航空公司在規劃航線頻次與機型時的影響。 在需求面方面，本研究考慮貨主之貨物起迄點、貨物價值、貨運量、貨物託運時間、以及航空貨運網路結構，並假設貨主以運輸成本與存貨成本總和最小為目標，構建貨主對運送方案選擇模式，以分析探討貨主的貨物特性、航空公司貨運航線機型與頻次規劃、及運送費率等的改變，對貨主於進行運送方案選擇時的影響。接著以網路模式與數學規劃模式為基礎，考慮其他競爭航空公司對航空公司貨運航線頻次與機型的調整是否有所反應，分別構建航空公司航線頻次與機型規劃模式及航空公司貨運航線庫諾競爭模式，並與貨主對運送方案選擇模式整合，在供需互動架構下，以最大化利潤為目標，規劃航空公司於其他競爭航空公司不同競爭策略與競爭行為下之最適航線頻次與機型。最後以一航空公司之貨運網路為例，並選擇其他航空公司為競爭者，蒐集實證分析中之相關資料，以驗證本研究模式在實際應用之可行性，並針對模式中的重要變數進行敏感度分析。 研究結果顯示，貨物若需經由空運中心轉運時，貨主可選擇空運中心與起、迄機場兩者間距離差異最小的運送路線，以降低運輸成本的負擔；隨著起迄機場間距離的增加，貨主將傾向選擇以大型機型營運的航線；隨著貨物時間價值的增加，貨主將傾向選擇直運路線，以節省存貨成本。此外，就模式中主要參變數進行敏感度分析，發現航空公司各貨運航線初始機型的規劃、運送費率訂價乘數的制訂，對航空公司於競爭市場上之利潤水準與市場佔有率的影響頗大。另外，本研究深入分析貨主之運送方案選擇行為、航空公司之供給策略行為、競爭航空公司競爭策略、以及其間之相互關係，所構建之模式可提供航空公司在瞭解與掌握其貨運市場，以規劃航空公司各貨運航線之營運頻次與機型，而本研究成果將可提供航空公司因應貨運需求變動與競爭環境進行策略制訂之參考。

The interactions among airline cargo demand, route flight frequency, and aircraft type are of such significance to necessitate using system analysis approach on airline cargo network problems. Past studies concerning airline network design, and flight frequency determination were mostly focused on developing mathematical programming models, or aimed at designing solution algorithms for above models. Few studies integrated changes in cargo demand resulted from the competition between airlines into route flight frequency and aircraft type determination problems for airline cargo network. On the other hand, most of studies concerning airline competition merely apply economic theory or statistical method to deal with air passenger markets; while few of them combine economic theory and network model to deal with air cargo markets and network design. In response to these, this study will explore airline cargo demand and network design problem via constructing models based on the combination of network model and economic theory to reflect the close demand-supply interaction in a competitive air cargo market. This study develops a model for determining the optimum flight frequency and aircraft type on each of all routes operated by an air cargo carrier in a competitive environment. The model is composed of two submodels which include a shipping alternative choice model for shippers and a route aircraft type and flight frequency planning model for airlines. The shipping alternative choice model assumes shippers with different demand characteristics choose the alternative with the least transportation and inventory costs among a choice set which comprises a variety of alternatives represented by competitive airline route service. The route aircraft type and flight frequency planning model is formulated using mathematical programming model by maximizing airlines’ profits to determine the optimum aircraft type and flight frequency on each routes under many-to-many demand pattern. The demand-supply interactions between air carriers and shippers are analyzed by integrating two submodels. The study also designs the solution algorithm to determine the optimal air cargo flight frequency and aircraft type on each of all routes. Finally, we illustrate a real airline cargo network and collecting necessary data to prove the feasibility of the model and to show the significance of results. The results of the study not only can be a building block for future studies in the area of air cargo market and network design problems, but can shed light on marketing, route flight frequency and aircraft type planning related issues for air cargo carriers to be competitive in response to changes in demand.