Due to the delicate structures of a micromachined component, the analysis of machining errors is a difficult task. However, in order to optimize the machining outcome, it is necessary to identify the source of the errors. By using a CT measurement of the machined workpiece in combination with a process simulation, it is possible to analyse deviations from the target geometry and the machining process in detail so that the causes for the deviations can be determined and resolved. An exemplary procedure for a micromachined test workpiece is presented in this paper.