Abstract: When producing injection-moulded or die-cast articles the changeover point between a filling program and a subsequent hold pressure program is determined by measuring the pressure inside the mould cavity at regular intervals, and deriving two classification variables (k.sub.0.sup.+, k.sub.0.sup.-, k.sub.-1.sup.+, k.sub.-1.sup.-, k.sub.-2.sup.+, k.sub.-2.sup.-) from each of the last three measured values (p.sub.0, p.sub.-1, p.sub.-2) in classification stages (K.sub.0, K.sub.-1, K.sub.-2) and combining them into weighting variables (g.sup.-, g.sup.0, g.sup.+) in a logic stage (V) using the methods of fuzzy logic. In an evaluation stage (A), by means of evaluation functions a switching value (s) is derived from these and compared with a threshold value in a decision stage (E). If the switching value oversteps the threshold, it is deduced that the changeover point has been reached.