現今航空運輸業面對競爭激烈的市場環境，容易受到政治、經濟，以及油價漲幅等環境因素導致虧損，甚至倒閉的情形也時有耳聞，而對於航空運輸業來說，任何能增加營收的來源都值得重視，因此各家航空公司進入機上免稅商品的市場，運用各項促銷方式，以及便利銷售通路，以期讓搭機旅客願意增加消費額。本研究採取模糊德菲法 (Fuzzy Delphi Technique, FDT) 及層級分析法 (Analytic Hierarchy Process, AHP) 來分析機上免稅商品銷售模式，研究結果發現在個別觀點方面，雖然各領域之航空運輸專業人士有不同的重視因素，但主要集中在企業服務品質；在整體觀點方面，企業服務品質係為機上免稅商品銷售主要關鍵因素，因此本研究建議航空公司應優先提升服務品質為首要任務。

Due to marketing competition, the aviation industry was likely lead to losses by environment factors, such as politic, economic and oil price. Taiwanese airlines tried to take an advantage of duty-free sales to increase profits. The purpose of this study applied fuzzy Delphi technique, FDT and analytic hierarchy process, AHP to analyze assessment model of duty-free goods for sale in Taiwanese airlines. The results find that experts from different fields have individual preferred indicators. However, the empirical study indicates that service quality is the most important criterion considered in overall experts. The analysis of this investigation suggests that the Taiwanese airlines must evaluate service quality first.