FMECA of NC Machine Tool Manufacturing Stage Based on Fuzzy Mathematics and Data Envelopment Analysis

In order to solve the problem that it is difficult to determine the occurrence probability of FMECA process failure in the manufacturing stage of CNC machine tools and there is no reasonable scientific basis when RPN is obtained, fuzzy mathematics theory and data envelopment analysis DEA are applied to the research of FMECA in the manufacturing stage of CNC machine tools. Considering the technological requirements and fault probability, fuzzy interval method to determine risk factors of degrees, using the data envelopment analysis method to evaluate the potential failure mode to get the efficiency value, to modify the traditional RPN, put forward a new method for calculating risk priority number of RPN, and then to sort of process failure mode, Find defects and weak links in production process and provide reference for improvement of production process. Taking the assembly process of a machining center as an example, the proposed method was applied to analyze the fault mode and its influence, and the effectiveness of the proposed method was verified.