A method for monitoring a modern state Anlagegutsystems involves the use of a plurality of auto-associative neural networks to determine estimates of actual values which are measured by a plurality of operating areas of the at least one sensor in at least; determining a residual error between the estimated measured values and the actual values, which are measured by the at least one sensor from each of the plurality of auto-associative neural network; and a combination of the residual errors by using a fuzzy model monitoring mixer; a performing a fault diagnosis on the combined residual errors; and a determination of a change in the operating Anlagegutsystems by analysis of the combined residual error. An alarm, if required, generated. A smart sensor system (10) includes an integrated processing unit (11) for performing the method according to the invention.