In a method for controlling a metallurgical production plant by means of a microstructure model, which comprises a program which calculates at least one mechanical strength property of a product being produced, which program calculates the strength property on the basis of calculated metallurgical phase components of the microstructure of the produced product, wherein the metallurgical plant comprises a terminating cooling line, and wherein operating parameters for the metallurgical plant with adjustable output values, which are established at least partially in advance, are factored into the calculation of the mechanical strength property, the object of the method is to enable an advantageous adjustment of operating parameters in order to achieve desired mechanical strength properties in a product consisting of a metal steel and/or iron alloy. This object is achieved in that, as the operating parameters that are factored into the calculation of the strength property, the mass fraction of at least one alloy element that is present in the chemical composition of the metal steel and/or iron alloy being used, and at least one additional operating parameter, preferably a cooling rate which is set as part of a cooling process carried out after a rolling process, are detected, and an increase in the strength property in question of the produced product, said increase being achieved by modifying at least said additional operating parameter, is at least partially compensated for by reducing the mass fraction of one or more of the alloying elements of the metal steel and/or iron alloy being used.