Method for heat treatment of a metallic product, in which the product is led through a furnace device, which is regulated by means of a regulating device, at a predetermined speed in a conveying direction, wherein the product is heated until reaching a first location and subsequently thereto is cooled until reaching a second location or a third location, wherein the second or third location as viewed in the conveying direction of the product is each downstream of the first location, characterised by the further steps of: (i) determining a quality window for the product at the second location or at the third location with respect to the austenite fraction, wherein the quality window is defined by a minimum value and a maximum value, wherein the minimum value and maximum value with respect to the austenite fraction are derived from at least one mechanical property of the product determined by measurement and/or in the laboratory, (ii) predicting a temperature for the product at the second location or at the third location by solving a heat transfer equation as a function of a temperature of the product at a position upstream of one of the second location or the third location and/or in dependence on the speed of the product, (iii) predicting the austenite fraction of the product at the second location or at the third location by means of a data-based model on the basis of the temperature predicted according to step (ii), and (iv) if an austenite fraction of the product predicted for the second location or third location according to step (iii) lies outside the quality window of step (i): adaptation of the speed of the product in the conveying direction by means of the regulating device in such a way that the austenite fraction of the product predicted for the second or third location comes to lie or lies within the quality window, wherein the speed of the product in the conveying direction serves as a setting variable for the regulating device. (i) determining a quality window for the product at the second location or at the third location with respect to the austenite fraction, wherein the quality window is defined by a minimum value and a maximum value, wherein the minimum value and maximum value with respect to the austenite fraction are derived from at least one mechanical property of the product determined by measurement and/or in the laboratory, (ii) predicting a temperature for the product at the second location or at the third location by solving a heat transfer equation as a function of a temperature of the product at a position upstream of one of the second location or the third location and/or in dependence on the speed of the product, (iii) predicting the austenite fraction of the product at the second location or at the third location by means of a data-based model on the basis of the temperature predicted according to step (ii), and (iv) if an austenite fraction of the product predicted for the second location or third location according to step (iii) lies outside the quality window of step (i): adaptation of the speed of the product in the conveying direction by means of the regulating device in such a way that the austenite fraction of the product predicted for the second or third location comes to lie or lies within the quality window, wherein the speed of the product in the conveying direction serves as a setting variable for the regulating device.