A new failure mode and effects analysis model of CNC machine tool using fuzzy theory

Failure mode analysis is important in CNC machine tool. In order to assess the failure mode of CNC machine tool, this paper described a new fuzzy FMEA model integrating with fuzzy linguistic scale method. The model proposed a risk-space diagram to explicit the relationship of S,O and D. On the basis of the risk-space diagram, risk priority number is calculated by weighted Euclidean Distance formula and centroid defuzzification based on Alpha-level. This study is used to analysis a type of CNC lathe. Compared with the criticality ranking about another similar type of CNC lathe, the risk ranking of FMEA model revealed that the method is basically same with the actual situation. The results indicated that the fuzzy FMEA used in CNC lathe is a reasonable method corresponding to the manufacturing, and it is a validity foundation for constructing reliability design model or supporting control plan of manufacturing.