from cycle to cycle our example application falls within this category the other scenario is where the actuator operation does not move in a cyclical or pseudo cyclical pattern in order to evaluate the actuator performance a quantitative method must be found to describe deviation from optimum performance in the following this will be called a u201c merit function u201d a typical merit function can be built from one or more of the following types of component evaluation functions each of them generating a numerical value characterising the actuator performance deviations from desired operation timing deviation from desired position deviation from desired velocity deviation from the demand curve accumulated over the whole or parts of the demand curve operation outside the safe operational range or operation which is close to the limits of the operational range in all of the above cases the merit function components must be based on an understanding of the operational states of the actuator and must be defined in each case the modular map normally uses a vector of independent numerical values as its input so the merit function can be built as a multi dimensional vector using each component of the merit function as a vector element this instance of the modular map is trained on a representative set of merit functions generated from the system this set of data can be the same dataset as the one used by the first instance of the modular map but not necessarily the map is labelled by using appropriate correction factors which are suitable for correcting the actuator behaviour the correction parameters are envisioned as being small in number in our example application a possible set of parameters to be adjusted can consist of four data points onset of movement duration.