For controlling a process, manipulated variables for a plurality of actuators that act on the process are calculated in a control device from measured values for output quantities of the process. To optimize the control of the process by control device (7), the actuator efficiencies (w.sub.11, . . . w.sub.nm) that describe the dependence of the changes in the output quantities (dy.sub.1, . . . , dy.sub.m) on the changes in the manipulated variables (du.sub.1, . . . , du.sub.n) for each actuator are learned in a neural network (10) and sent to the control device (7) to improve the calculation of the manipulated variables (u.sub.1, . . . , u.sub.n)