“…), with adjustment of scan conditions such as sampling frequency, then the recovered data will be stored for further processing which can be expensive in time [33], In a data-driven approach, there are two methods for estimating from historical data, which are direct and indirect. The indirect method relies on the construction of the HI to be able through a model to go back to RUL, by contrast, direct method allows to estimate directly RUL from data [34]. Now, move on to the second stage, which is Health Indicator (HI) construction, in this stage, seek to find an indicator reflecting cutter health stat from the acquired signal, several works have been done in this framework, always looking for an indicator that represents the most monotonicity and reflects the degradation of the component to be studied [35].…”