航空公司最適裝載設備調度與規模之研究

Abstract

航空公司裝載設備 (Unit Load Device, ULD)為裝載旅客行李與空運貨物之主要載具，ULD年度的規模規劃為航空公司營運之一項重要決策。本研究乃探討航空公司ULD年度規模規劃之問題，其中包含兩項關鍵的議題：1)決定各場站ULD安全庫存水準及2)ULD在航空網路內之最佳數量與調度。因此本研究首先提出一系統性的方法，制定各場站ULD安全庫存水準。針對航空網路營運之特性，本研究考量：1)航班ULD載運需求及各場站ULD 安全庫存水準；2)航班容量限制及重量限制；3)運用SKYPOOLING平台之ULD的彈性；與4)空ULD堆疊轉換等限制。運用時空網路技巧，本研究建立線性整數規劃模式，求解ULD在航空網路內之最佳規模與調度，以最小化ULD營運總成本。運用個案航空公司的歷史數據對於本研究的研究方法進行驗證與比較分析，並對於不同的服務水準下產生ULD規模規劃。觀察到個案航空公司現行使用ULD規模與本研究所得之最佳ULD規模非常接近，且敏感度分析結果顯示個案航空公司因為善用場站間自有ULD之調度與運用SKYPOOLING平台之調度，故無須建置過大之ULD規模。透過數據實證本研究所發展之系統化方法，可以協助個案航空公司進行ULD年度規模規劃，成為有效的決策輔助工具。

The Unit Load Device (ULD) serve as major equipment for loading passenger baggage and air cargo, and the annual scale planning of ULD is an important strategic decision for airline companies. This study focuses on solving the ULD scale planning problem for the airlines, that includes two crucial issues: 1) determining the safety-stock level of ULD in each station, and 2) the optimal number and dispatching of ULD in the aeronautical network. We propose a systematic approach ULD for the determination of safety-stock level in each station. Also, we take into account the following considerations when solving the optimal dispatching of ULD, namely, 1) the demand of ULD for the flights of carriers and the safety-stock level in each station; 2) the capacity limits and weight limits of each flight; 3) the flexibility of utilizing ULD from SKYPOOLING; and 4) the stack conversion and other restrictions of empty ULD. Using the modeling techniques of space-time network, we formulate a linear integer programming model to determine the optimal number and dispatching of ULD to minimize the total operating costs. Based on the historical data of an airline in our case study, we conduct verification and comparison analysis for the proposed methodology in this study by generating scale-plans for different service levels. We observe that the current ULD scale in the case airline is close to the optimal scale plan, and our sensitivity analysis indicates it is not necessary to build a larger scale of ULD since the case airline makes good use of the self-owned ULD dispatching among stations and those dispatching from SKYPOOLING platform. Our numerical experiments show that the proposed systematic approaches in this study may assist airline in solving the ULD scale planning problem and serve as effective decision-support tools.