An injection molding system with a by a control unit (5) regulated the basis of predetermined control parameters such as injection speed, holding pressure, holding pressure time and mold temperature injection device (4) has an evaluation unit (11), each based on a pressure profile, by means of a close to the gate in a cavity (2) arranged pressure sensor (12) is detected, checks the control parameters on the existence of an Nachregelungsbedarfs and corrected if necessary. Here reference values ​​are respectively from the pressure curve, usually by reference to a corresponding one good part reference curve, determined from which by means of a neural network, a review of the control parameters is derived. If z. B. found border at least two preceding shots certain thresholds interpretive on too high deviations assessing the holding pressure, so it is multiplied for the next shot with an equally determined correction factor <1. The pressure variation in the filling phase is controlled by a result of the pressure curve made with methods of fuzzy logic adjustment of the profile of the injection rate so that he as much as possible approximates a straight line.