A concept where the air traffic operations of ATM community members are such that the successive planning and operational phases of their processes are managed and can be achieved in a seamless and coherent way.
ICAO (2008), doc. 9882, Manual on Air Traffic Management System Requirements
Gate-to-gate is a concept that involves considering and managing a flight as a continuous event, from planning, through execution, to the post-flight activities. Its scope extends from the first interaction of the flight with ATM (which for commercial flights may be up to 6 months ahead of the date of the flight), through the execution of the flight on its appointed day, to performance registration and the calculation of charges for the services received after it has taken place.
EUROCONTROL (2004), EUROCONTROL OPERATIONAL CONCEPT DOCUMENT, Vol. 1, Ed. 2.1