1. A method for optimizing utilization of a programmable logic element in an electronic control unit for vehicles, the programmable logic element comprising a soft CPU and/or an unused remaining area, the method comprising: generating a number of model variants that reproduce functionality of the control unit, the model variants differing in scope of computing operations to be executed by the soft CPU; generating a number of soft CPU configurations with differing configuration scopes, each soft CPU configuration occupying an area corresponding to a configuration scope on the programmable logic element; executing processor-in-the-loop simulations for different combinations of the number of model variants and the number of soft CPU configurations, the execution for each combination of model variant and soft CPU configuration includes: determination of a number of individual universal blocks in the programmable logic elements to be occupied for use by the soft CPU according to the soft CPU configuration; instantiation of the soft CPU corresponding to the soft CPU configurations on the programmable logic elements located on a development circuit board that is connected to a computer, wherein a program code corresponding to the model variant is downloaded from the computer to the soft CPU; and execution of a simulation program, wherein an input signal to be processed according to the model variant is simulated and is transmitted through an appropriate interface from the computer to the soft CPU programmed on the programmable logic elements; processing the input signal by the soft CPU; and acquiring and storing profiling data of the soft CPU with regard to the processing of the input signal, wherein the profiling data includes at least one of quantities of utilization of a RAM and/or a ROM, utilization of a stack, required execution time, or precision of computing operation.