Risk evaluation of NC machine tools based on fuzzy weighted geometric mean

According to the data collected from 23 NC machine tools from one type, based on the fuzzy FMEA model, a Failure modes Analysis have been carried out. Fuzzy linguistic variables were introduced into the analysis, and the three risk factors were given different weights, Each FRPNs of the failure modes were calculated by linear programming, and then the failure mode which influence the NC lathe the most have been pointed out, this results can provide useful basis on how to eliminate these failure models and how to improve the reliability of NC machine tools of this type.