1. A computer implemented method for monitoring a plurality of hardware or software system resources for identifying hidden trends in the behavior of the system resources, the method comprising: collecting metrics of at least one system resource indicative of the behavior of at least one system resource; for each of the at least one system resource, determining a spectrum representative of a time-based signal of the collected metrics; performing a wavelet transform on each of the at least one spectrum; analyzing the result of the wavelet transform to identify possible linear trends in the behavior of the at least one system resource; and assigning to each identified linear trend a severity value indicative of a criticality of the related behavior; assigning to each identified linear trend the severity value indicative of the criticality of the related behavior comprises: estimating, by means of extrapolation of the linear trend, a moment in time when a predetermined threshold of the related system resource will be reached.