Codesharing network vulnerability of global airline alliances

Global airline alliances provide connectivity based on codesharing agreements between member airlines. An alliance member exit leads to the deletion of routes (if not operated by other members) which affects network connectivity. The paper measures the vulnerability of the codesharing network (CN) of Star Alliance, SkyTeam and oneworld, respectively, by applying the theory of complex networks. A normalized CN vulnerability metric is proposed. Using airline schedules data, a ranking of member airlines according to their share in the overall CN vulnerability is derived. The results for CNs are compared with the ones for the respective total network (TN) that includes routes with and without codesharing. The findings show that oneworld is the most vulnerable global airline alliance, SkyTeam ranks second followed by Star Alliance. The proposed graph theory approach might become a building block for a more comprehensive measurement of real world airline networks.