1. A method for controlling an installation for producing steel, the steel having a microstructure and defined materials properties that are dependent on the microstructure and the defined materials properties can be influenced by operating parameters of the installation, the method comprising: prior to beginning a production process, entering into a computation program for microstructure optimization both (a) setpoint values defining operating parameters of the desired production process and (b) setpoint values for a desired chemical composition of the steel that define desired quantitative fractions for one or more chemical elements; the computation program for microstructure optimization: analyzing the entered setpoint values and predetermined dependencies between particular operating parameters and quantitative fractions for particular chemical elements, including analyzing data of a predetermined relationship between a quantitative content of a particular chemical element and a quantitative measure of at least one operating parameter used in one or more production steps of the steel production process, the data indicating modifications to the quantitative measure of the at least one operating parameter required to account for modifications to the quantitative content of the particular chemical element in order to provide a particular desired material property of the steel; and based on the analysis of the entered setpoint values and the predetermined dependencies between particular operating parameters and quantitative fractions for particular chemical elements, automatically modifying at the same time both (a) at least one of the setpoint values defining the quantitative fraction for at least one chemical element of the desired chemical composition of the steel and (b) at least one of the setpoint values defining operating parameters of the desired production process; and wherein, as a result of modeling the setpoint values for the desired chemical composition of the steel and for the operating parameters at the same time, at least the component material cost of the steel is reduced without reducing the material properties of the steel.