Continuous validation of the PHM function in aircraft industry

In the literature, most of Verification and Validation (V&V) papers deal with the design of a prognostics function and the verification and validation process necessary to put this function into service. Nevertheless, from an industrial point of view, even if this V&V procedure is successfully performed during the design and testing phase, it only considers data and knowledge available at the time the V&V procedure is carried out. However, it is possible that the systems evolve during operations causing a drift from the initial assumptions which could lead to a loss of performance, especially as the systems age. This paper aims at taking into consideration the total lifecycle of a PHM function, from the design and testing phase to the operation phase (after its entry into service).