A centralized maintenance system for aircraft which includes line replacement units (LRUs). The system includes at least one digital database whose data are information relating to the LRUs; and a device for updating the data of the database. The lifetime information for the LRUs is known and contained in the digital database. The database includes a mean time between failure (MTBF) data of each LRU. The MTBF data is able to be modified and updated, according to at least one event modifying the failure probabilities for at least one LRU.