In 2015, the Lufthansa Group disrupted the European travel sector by enforcing a surcharge on tickets bought via global distribution systems (GDS). This move deviated from the traditional GDS distribution model, encouraging travellers and agents to book directly on Lufthansa’s websites. This was met with criticism from corporate travel interests, who felt that Lufthansa had not considered their needs. This is not an isolated incident and is part of a complex history of managed travel. In the 1950s, IBM created a data processing system called SAGE for the US air defence system. This technology was later used to form the basis of the airline reservation solution following a chance meeting between an IBM salesperson and American Airlines CEO C.R. Smith.