1. A method for determining an operational status of a remote device comprising: building a performance history for the remote device; identifying standard measures of satisfactory, periodic performance from the performance history; determining current operational characteristics of remote device performance corresponding to the standard measure of satisfactory, periodic performance; identifying differences between a current operating status of the remote device and the current operational characteristics of remote device performance; and calculating a likelihood estimator to determine whether the differences indicate that the remote device is operating within acceptable variances from the standard measure of satisfactory, periodic performance or that the remote device is not functioning satisfactorily.