The rise of high speed manufacturing gave birth to high capabilities machine tools; meanwhile the constraints have increased. To face these challenges, several simulation solutions have been proposed. They cover many aspects of the manufacturing process such as CNC controller behavior, cutting forces estimation or geometric errors. However, most of them center on a specific view of the machining process. In contrast, combined multiphysics and multiscale approaches are beneficial, in particular for surface integrity improvements purposes. This paper discusses the interest of using simulation approaches at different levels. The first target is to analyze existing parameterizations. Then, a comparison of several parameters tuning extends the space of acceptable solution and provides new enhancements. Finally, a simulation method for form defect of machined surfaces identification is introduced. Several simulation solutions developed in the laboratory are taken as illustrative examples.