A method for producing long metal products includes the steps of receiving long intermediate products traveling on respective continuous casting lines, to an exit area, and subsequently introducing products from the exit area into a production plant having known layout parameters; the production plant has a rolling mill for rolling the products; interconnected production lines between the exit area of the casting machine and the rolling mill, the production lines define production paths or routes; and a first and a second heating devices. The method associates a mathematical model to the production plant for dynamically calculating a reference value, or Global Heating Cost Index, correlated to heating devices; automatically determining for the intermediate products the production path or route that minimizes the reference value, or Global Heating Cost Index; and eventually automatically routing each of the products along the determined production path which minimizes the reference value, or Global Heating Cost Index.