In this paper, we present a new diagnosis and prognosis method using degree of randomness (DoR) measure and Laplace test procedure. The abnormal events are detected through the measure of change of randomness of vibration signals. The changes of randomness are resulted from the faulty components such as roller bearings. We aim at the early detection of semi-failure events through the use of Laplace test statistic which measures the rate changes of the abnormal event occurrence. Test results using roller bearing data downloaded from NASA Prognostic Data Repository have shown that our algorithms can detect the roller bearing faults 10 days in advance of the occurrence of failure.