Method for the automatic monitoring of a production process, and a production plant and computer program therefor

A method for automatic monitoring of a production process, which is performed by a production plant for manufacturing at least one product, with

• at least one process quantity of a number of process quantities,
• at least one monitored process quantity of a number of monitored process quantities, wherein each monitored process quantity additionally belongs to the number of process quantities,
• and wherein
• a. at least one value of at least one indirect process quantity of a number of indirect process quantities is automatically determined from at least one—preferably past—value of at least one process quantity of the number of process quantities,
• b. for a number of reference quantities, at least one preliminary reference value is determined from the at least one determined value of at least one indirect process quantity of the number of indirect process quantities, wherein a preliminary reference value is respectively allocated to one reference quantity of the number of reference quantities and wherein one reference quantity is respectively allocated to at least one monitored process quantity,
• c. for the determination of a limited reference value of the at least one reference quantity, it is checked, whether the preliminary reference value of the at least one reference quantity lies within a range of reference values permitted to the reference quantity, wherein, if this is not the case, the preliminary reference value is transformed, preferably shifted, into the permitted range of reference values, and otherwise, the limited reference value corresponds to the preliminary reference value,
• d. it is checked whether at least one value of at least one monitored process quantity (1) of the current production process represents an anomaly with regard to
• i. at least one limited reference value of the at least one reference quantity, and/or
• ii. at least one composite reference value of a composite reference quantity, wherein the at least one composite reference value is determined from at least one limited reference value of the at least one reference quantity and at least one value of an indirect process quantity.