This tesi described the implementation of a new policy that will have an impact on the maintenance and services market of the civil air transport sector by directly impacting the MRO players of this market. Thales, which manufactures avionics equipment onboard aircraft from various manufacturers (Airbus, Boeing, ATR, ...) must allow all operators, to be able to fly with their aircraft over a long period of time and to maintain and maintain that equipment. Thales also enables third parties to maintain Thales equipment installed on aircraft and to provide them with access to the information and equipment necessary for their maintenance.