Example of optimization in national level air transport companies: Evaluation within regional aviation

Airline transportation is in a different position than other modes of transport with its dynamic and universal structure. Business requirements and passengers' expectations determine the direction of the differences. Regional airline transportation, which has become a more distinct flight type with the changing passenger market and demands in the last 20-25 years, composes the subject of the thesis. With its operational features, integration with other aviation activities and undertaking complementary role make regional airline transportation important. In this study, a two-stage decision-making method has been adopted to ensure operational efficiency for an airline company aiming to perform regional transportation. First of all, it is aimed to determine the flight route by choosing the airport where regional air transportation will be made. In the second decision stage, it is aimed to determine the types of aircraft that these flights will be operated on and used in regional aviation. In this decision making, AHP, TOPSIS and CODAS were used. In the study, Spherical Fuzzy Sets which is a new perspective on decision making methods and one of the 3 dimensional fuzzy sets approaches, with integration of these decision making methods are used. Spherical Fuzzy AHP-TOPSIS and Spherical Fuzzy AHP-CODAS methods are adopted as a hybrid decision making system for both airport selection and aircraft selection. It is aimed to make the most suitable choice among the alternatives by making a comparative analysis of both methods.