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; assigning to each identified linear trend a severity value indicative of a criticality of the related behavior wherein the criticality of behaviors comprises an indication of how fast a predetermined threshold of the related system resource will be reached; and ranking the severity value with respect to at least one other severity value to identify an order in which to address the behavior of the at least one system resource.