Supervision of industrial plants can be improved by comparison and analysis of process information and network information. The comparison may be used to provide alarms and operator information for network-related or process device failures. The information may also be used to identify a cause of a failure. A method is described for supervising an industrial control system, including a plant network for supervision, a client/server network for server connection with workstations, and a control network connected to industrial controllers. The method comprises the steps of gathering process information, and gathering network information, and by comparing information provided by data communications network monitoring with process control information and using the result of the comparison to assist in determining a cause of a problem or possible problem in a process controlled of the industrial control system.