Identifying a cause of a fault based on a process controller output

Abstract

A method and apparatus is provided for identifying a cause of a fault based on controller output. The method comprises processing at least one workpiece under a direction of the controller and detecting a fault associated with the processing of the at least one workpiece. The method further includes determining a plurality of possible causes of the detected fault, identifying a more likely possible cause out of the plurality of possible causes, providing fault information associated with the identified more likely possible cause to the controller. The method further includes providing fault information associated with the identified more likely possible cause to the controller. The method further comprises adjusting the processing of one or more workpieces to be processed next based on the fault information provided to the controller. The method further includes generating prediction data associated with processing of the next workpieces, and comparing the prediction data to processing data associated with the processing of the next workpieces to identify a possible cause of the fault.