A Comparison Between Fuzzy TOPSIS and VIKOR to The Selection of Aircraft for Airspace Defense

Since 2013, the Spanish fleet of EF-18 fighters has not received major updates nor any other jet has been proposed for their replacement. Thereby, a decision problem of interest to the Spanish Air Force is addressed in this study. In this regard, a collection of six potential alternatives (Eurofighter Typhoon, F-35 Lightning II, F/A-18 Super Hornet, Dassault Rafale, F-15 EX, and Saab 39 Gripen) and 14 criteria (3 of which being qualitative) are evaluated based on expert consensus by a combination of fuzzy logic and multi-criteria decision making (MCDM) approaches (AHP-VIKOR/AHP-TOPSIS). The weights of the criteria and the valuation of the qualitative ones (via questionnaires) were made possible by the participation of two independent groups of experts, all of them fighter pilots. Once the extraction of knowledge was carried out via a fuzzy version of a modified AHP, it was found that the two most important criteria (“air superiority over neighbor countries” and “tactical capability”) were qualitative. A comparison between the rankings of the alternatives provided by fuzzy VIKOR and fuzzy TOPSIS approaches highlights that the fuzzy VIKOR ranking appears highly influenced by the most important criteria. On the contrary, fuzzy TOPSIS presents a more compensatory behavior than fuzzy VIKOR. Given the differences observed when comparing such rankings of alternatives, a triple sensitivity analysis was conducted to ensure robustness. Our results highlight the Dassault Rafale as the most promising option for replacement. This finding suggests its potential as a benchmark for future fighter selection and next-generation fighter planning.