A flight management system includes: an avionics core implementing generic aircraft management functionalities and providing services associated with the generic functionalities; at least one remote functionality in an open world part performing a function of interfacing between the avionics core and the open world applications run on the open world part which need to communicate with the avionics core, wherein the remote functionality ensures homogeneity and consistency of data exchanged and guaranteeing integrity and security of data exchanges, and an exchange interface of between the avionics core and the open world functionality supporting data exchanges.