Method for heat treatment of a metallic product (P), in which the product (P) is led through a furnace device , which is regulated by means of a regulating device , at a predetermined speed in a conveying direction (F), wherein the product (P) is heated until reaching a first location (I) and subsequently thereto is cooled until reaching a second location (II) or a third location (III), wherein the second or third location as viewed in the conveying direction (F) of the product (P) is each downstream of the first location (I), characterised by the further steps of: (i) determining a quality window for the product (P) at the second location (II) or at the third location (III) 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 (P) determined by measurement and/or in the laboratory, (ii) predicting a temperature for the product (P) at the second location (II) or at the third location (III) by solving a heat transfer equation as a function of a temperature of the product (P) at a position upstream of one of the second location (II) or the third location (III) and/or in dependence on the speed of the product (P), (iii) predicting the austenite fraction of the product (P) at the second location (II) or at the third location (III) 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 (P) predicted for the second location (II) or third location (III) according to step (iii) lies outside the quality window of step (i): adaptation of the speed of the product (P) in the conveying direction (F) by means of the regulating device in such a way that the austenite fraction of the product (P) predicted for the second or third location comes to lie or lies within the quality window, wherein the speed of the product (P) in the conveying direction serves as a setting variable for the regulating device . (i) determining a quality window for the product (P) at the second location (II) or at the third location (III) 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 (P) determined by measurement and/or in the laboratory, (ii) predicting a temperature for the product (P) at the second location (II) or at the third location (III) by solving a heat transfer equation as a function of a temperature of the product (P) at a position upstream of one of the second location (II) or the third location (III) and/or in dependence on the speed of the product (P), (iii) predicting the austenite fraction of the product (P) at the second location (II) or at the third location (III) 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 (P) predicted for the second location (II) or third location (III) according to step (iii) lies outside the quality window of step (i): adaptation of the speed of the product (P) in the conveying direction (F) by means of the regulating device in such a way that the austenite fraction of the product (P) predicted for the second or third location comes to lie or lies within the quality window, wherein the speed of the product (P) in the conveying direction serves as a setting variable for the regulating device . <EOS>