A method for implementing FDC in an APC system including receiving an FDC model from memory; providing the FDC model to a process model calculation engine; computing a vector of predicted dependent process parameters using the process model calculation engine; receiving a process recipe comprising a set of recipe parameters, providing the process recipe to a process module; executing the process recipe to produce a vector of measured dependent process parameters; calculating a difference between the vector of predicted dependent process parameters and the vector of measured dependent process parameters; comparing the difference to a threshold value; and declaring a fault condition when the difference is greater than the threshold value.