The plant (A) has a melt-producing upstream plant section interlocked with a preform producing injection molding plant section (2) to form a plant block (B) for direct processing of a produced melt to preforms (P) in the injection molding plant section for deriving process alteration strategies and preform qualifying strategies and a combination of both the strategies. An inline measurement station (9) with an evaluating device (21) is provided between the interlocked plant sections at an interface (4) for providing a quality parameter of a melt measured during the operation of the plant. An independent claim is also included for a method for continually producing preforms for plastic containers for filling of foodstuffs.
