Basis for processes performing on the surfaces under exploitation is the pattern of the microgeometric structure. Depending on the applied machining technology, differently featured and oriented micro valleys and peaks are formed later taking active participation in the processes of bearing with statical and dynamical loads, friction, lubrication, failures etc. Computer models of the surfaces microgeometric structure with machining parameters as parameters of the model enable simulation of exploitation processes and analysis of the corresponding changes on the surface. With this aim, some of the theoretical formulations for such software simulations on previously designed surface models are presented in this paper, as well as the possibilities to determine the exploitation properties following the change of the corresponding roughness parameters. This way, analyzing the models created in 3-D domain, we become able to predict the functional behavior of the real machined surface, but of course with certain degree of uncertainty.