A Multi-Criteria Solution Approach for the Alternative Preventive Maintenance Applications in the Aviation Industry

Abstract

For the aircrafts to continue their operations actively, implementing systematic maintenance to the aircrafts are required by the aircraft manufacturers and civil aviation authorities. These operations are carried out by the aircraft operating companies as a priority. How often and at what levels the maintenance will be applied is specified in the maintenance manual published by the manufacturers. The maintenance to be performed varies depending on the mission feature of the aircraft, the flight time, or a certain calendar period. The aviation administration periodically classifies the maintenance concepts to be applied according to the frequency of maintenance by taking advantage of the maintenance criteria determined in the maintenance manual. In this classification, the maintenance operations are arranged based on "preventive maintenance" for the aircrafts to continue their activities effectively. The applied maintenance concepts are determined in the military and civilian sectors in accordance with the intended use of aircraft. In this study, in terms of the criteria determined by the application of Multi-Criteria Decision-Making methods in the literature, the most critical aircraft parts for the alternative preventive maintenance applications were identified with the real data of the Cessna 172 Skyhawk training aircrafts. After determining the criterion weights with AHP (Analytical Hierarchy Process) method, the most critical aircraft parts were prioritized with the AHPweighted TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) method. The criteria considered in the study are the unit cost, the lead time, and the total number of failures in a year of the aircraft part. Then, the reliability analyses are performed to suggest an alternative age-based preventive maintenance policy. In accordance with this purpose, real failure data are analyzed to find failure probability distributions, mean times between replacements, and cost efficiency values of each critical part. As a result, an alternative preventive maintenance policy is suggested for each critical aircraft part by determining the optimal maintenance intervals where the preventive maintenance is cost-effective. The proposed study is intended to provide guidance for alternative preventive maintenance practices in the airline industry.