Method for the monitoring of a plant

A method for the monitoring of a plant having a plurality of sub-systems which is operable at variable working points and comprising the following steps:

• a) respective measured values are detected for a fixed set of process parameters (B, U, S1, . . . , SN) at pre-settable time intervals during the operation of the plant (1);
• b) the measured values detected in a learning phase for different working points are used to prepare models (M1, M2, . . . , MN) for the operating characteristics of the sub-systems (11, 12, . . . , 1N), with the input values of each model (M1, M2, . . . , MN) being at least a part of the process parameters (B, U, S1, . . . , SN) and the output value of each model comprising a model value (Yi, Yik) for at least one of the process parameters, and with the models (M1, M2, . . . , MN) being optimised by comparing the model values with the measured values;
• c) at least one monitoring parameter (Ri, Rik), which is independent of the respective current working point, is determined at pre-settable time intervals in an operating phase using the models (M1, M2, . . . , MN);
• d) the time-dependent course of the monitoring parameter (Ri, Rik) is used for the monitoring of the plant (1);
• characterised in that a pre-check (2) is carried out prior to the determination of the monitoring parameter (Ri, Rik), in which a check is made whether at least the measured values for those process parameters which are operating parameters (B) are within a pre-determined range.