Abstract: A method for controlling and optimizing the operation of a series of interdependent processes in a plant environment. Manipulation of one or more constrained process input variables is used to achieve feedforward/feedback control of one or more process output variables. In the synthesis of the method of controlling and optimizing, input variables are subjected to measured perturbations and the dynamic effects on the outputs are noted for prediction of the future response of the processes during on-line operation. Time variant and time invariant constraints on system operation are incorporated to allow optimum operation of the interdependent processes.