6. Conclusions The comparative calculation values, obtained for determining the priority ranking of the maintenance tasks by CFA method are complete and more realistic compared to the results of conventional FMEA. If only the RPN values are taken into account in prioritizing the maintenance tasks, then the highest level of reliability is obtained, but with high costs. The minimum CNC machine tools reliability and maintenance costs are the main constraints considered in the CFA method. By applying the new method, it was demonstrated that the implementation of a preventive maintenance is often financially unjustified. Applying this method on the given example shows that a reduction in maintenance costs can be obtained by reducing the number of preventive actions, while maintaining a minimum acceptable reliability level. Judging the problem by the CFA method, it is found that to evaluate a CNC machine tool for planning maintenance actions, it is not necessary to spend time for evaluating critical components, which can be done later. First, it must be determined if preventive maintenance action turns out to be less expensive than the failure.