民用航空發動機提供民用航空飛機動力，滿足民用航空運輸業載客與運貨的需求，然而發動機使用運轉後需定期更換，進廠維護或翻修，確保在翼運轉及操作可靠度。發動機維修費用昂貴幾乎佔據整個飛機維修費用的四成，如何同時維持發動機的可靠性，又能降低維修成本，一直是航空公司努力的方向。發動機維修部門首重發動機出廠交期(Turn Around Time，TAT)，即發動機進廠到出廠的所有維修時間，交期若能準時穩定，可精準發動機進場維護時程、有效地實行維護計畫與排程，進而提昇飛航安全，降低航空公司營運成本；若能進ㄧ步縮減TAT，可減少備份發動機數量，出售或出租多餘的備份發動機，增加公司營收；另外，短且準時的交期，增加本身競爭力及承攬發動機維修的能力，創造營收商機。
為達成縮減發動機翻修TAT重要目標，本研究藉著個別關鍵翻修流程TAT縮減最佳化，達到整體TAT縮減極大化，以現場工作實務經驗，解構歸納翻修主要關鍵流程，提列足以改善、縮減流程TAT的可能作法，先篩檢出限制條件，後建立目標函數、然而各個流程存在多個可行方式，彼此間因資源有限及目標衝突，無法全部選擇實施，本研究運用多目標規劃理論找出所有可行解。一旦獲得各流程改善可行解，同時使用分析層級程序法，將牽涉到眾多考慮因素之複雜決策問題建構層級，由決策者逐層評斷各評估因素之相對重要性，判斷出各決策方案之優先順序，作出縮減交期的最佳決策，期望對附屬於個案航空公司的發動維修單位提出改善方向與建議。;American Wright brothers drove self-developed fixed wing plane in 1903, that realizing the motive force fly for the first time in the human history, over 100 years past, the airborne vehicle even aviation industry have grown vigorously, have expanded human scope of activities and pace substantially, rewrite the history of human transportation completely. Though once there was a period of prosperity in the aviation industry, as the international crude oil price was going up constantly, purchase the oil expenditure and account for the proportion of the operating cost of the airline have soared year by year, in addition, terror has been threatened constantly since September 11 attacks of U.S.A. and violent competition among the same trade, the depression causes the market of aviation to shrink gradually, it will be difficult to make a profit. How to reduce operating cost, create niche and increase revenue, already become an airline′s important existence subject.
The civil aero-engine has being offered the power of civil airplane, meet the demand that transport service of civil aviation carries passenger and freights, however, the engine is used for operations, needs to be changed regularly, and enter the shop for maintenance or overhaul in order to guarantee engine on wing operation and reliability. The maintenance cost of engine nearly occupies 40% of the maintenance cost of whole plane, to maintain the engine reliability and reduce the maintenance cost at the same time, it has been airline′s diligent direction all the time. It is the most important task to maintain the engine Turn Around Time(TAT) for an Engine Shop, the time between engine enters the shop for maintenance and dispatched from the factory, If TAT can be maintained accurate and on time, the engine shop in for maintenance schedule will be stable, implement the maintenance program and arrange planning effectively, and then ensure the flight security, reduce the operating cost of the airline; If engine shop can further reduce TAT, spare engine quantity for fleet supporting will be able to reduce, to sell or loan out the extra spare engine can increase airline’s revenue; In addition, a short and punctual TAT will increase shop own competitiveness and contract the engine to maintain ability, raise the company’s profit and create the business opportunity.
In order to achieve the important goal of engine TAT reduction, this study is making use of the improvement or rebuilding the key procedure to reduce TAT in the optimization, then reach whole TAT reduction in the maximization, with the practice experience of the work in the shop, constructs and sums up the rebuilding of the main key overhaul procedure, propose and tabulate the possible practice sufficient to improve and reduce procedure TAT, sift and examine the limiting conditions out first, and then set objectives formula, but a lot of feasible solutions exist in each procedure for the function, because resources are limited and goal conflict between each other, unable all choose to implement, this study uses Multiple Objective Programming method to find out all solutions while being feasible. Once feasible solutions of every procedure have been obtained, use Analytic Hierarchy Process method at the same time, the complicated decision question that will involve numerous considerations builds the level of constructing, the policymaker chases one layer of relative importance which judges every factor of evaluation, judge the priority of every decision scheme, make the best decision of the TAT reduction, expect it is the engine maintenance shop that affiliating to the airline to propose improving direction and suggestion of the case airline.