How do costs influence Electric Vertical Take-off and Landing aircraft selection?

In order to find a solution to maintain the market share on the banned ultra-short-haul routes, an airline can consider replacing conventional aircraft with an electric Vertical Take-Off and Landing aircraft (eVTOL). To make a satisfactory choice (among six eVTOLs: Joby S4, Lilium Jet, Terafugia TF-2 Lift+Push, Alice, Jaunt, and Embraer Flexcraft) while dealing with multiple criteria, the Analytic Hierarchy Process (AHP) approach can be applied. The sensitivity of eVTOLs’ rankings concerning different pairwise comparisons of the alternatives with respect to costs is analysed, showing the influence of cost changes on aircraft selection. The sensitivity analysis shows that the final rank of six aircraft is sensitive to cost changes. It was conducted 720 experiments, 120 per aircraft having the lowest costs. That means that all possibilities have been exhausted and the set of all feasible solutions has been searched. Moreover, for defined pairwise comparison matrix of criteria selected (the first level of hierarchy), it is revealed that Terafugia TF-2 Lift+Push, can never be chosen as the most desirable solution, Alice and Embraer Flexcraft can never be bottom-ranked, while the other three aircraft can be both the best and the worst solution.