The disclosure concerns a method for model-based optimization, especially calibration, of a technical device, especially an internal combustion engine. The method may involve the following steps: detection of at least a first parameter in relation to the technical device being optimized which characterizes a physical quantity; first determination of at least one second parameter in relation to the technical device being optimized by at least a first physical model which characterizes at least one known physical relationship and for which the at least one first parameter is an input parameter; second determination of at least one third parameter by at least one first empirical model based on measurements on a plurality of already-known technical devices of the same kind, especially internal combustion engines, and for which at least the at least one second parameter is an input parameter, wherein the at least one third parameter is suited to characterizing the technical device being optimized and/or to providing a basis for making a change in the technical device being optimized, especially to adjusting a control unit of the technical device being optimized; and outputting the at least one third parameter.