Abstract: An industrial process (2) is simulated in which the value of each physical magnitude P.sub.i characteristic of its state is varied at a rate of change V.sub.i that is a function of the state of control signals (3) emitted by an automatic controller (1), and which reports its state to said controller by means of state signals (4) which are emitted by sensors as a function of the values of the respective physical magnitudes that they monitor. For each physical magnitude P.sub.i, the time interval .delta.t.sub.i is determined during which the value of the physical magnitude can change without any of the sensors monitoring said physical magnitude P.sub.i changing state. Thereafter the value of each of the physical magnitudes P.sub.i is updated by incrementing its value by the product of the corresponding rate of change V.sub.i multiplied by the smallest of the above-determined time intervals .delta.t. Finally, after updating the sensors monitoring each of the physical magnitudes P.sub.