Complex equipment of an industrial plant subject to control, large body of information flows, complexity of control problems, lack of time available to make a decision, etc. are the reasons which lead for a number of cases to contradiction of human-operator control capabilities and actual control problem requirements. Within such a problem, a natural way out is to design an intelligent information support system (IISS) which would be able to assist the human-operator to implement complex industrial plant control functions. The functions are to involve operative mode control of automatic systems, monitoring the systems performance, and prediction of the plant status, both within normal and abnormal situations. Involving the IISS into the control process enables one to decrease the human-operator load, to increase the human-operator performance, and to increase the plant performance reliability.