Method and apparatus for recognizing a fault state of a machine or of a process

An apparatus (100) for recognizing a fault state of a machine (102) or of a process, wherein the apparatus (100) is configured to detect actual values of parameters of the process at the machine (102) for carrying out the process, wherein the parameters comprise at least one controllable process parameter (204) of the process, at least one non-controllable process parameter (206) of the process or at least one control parameter (202) for controlling the or another controllable process parameter (204) in the process, wherein the apparatus (100) is configured to predefine a target correlation for actual values of at least two of the parameters, to determine an actual correlation depending on the actual values of the at least two of the parameters, and to recognize a fault state of the machine (102) or of the process depending on the actual correlation and the target correlation, wherein the apparatus (100) is configured, depending on the target correlation, to predefine a corridor for the actual correlation, to recognize that the actual correlation lies outside the corridor, and to recognize the fault state if the actual correlation lies outside the corridor.