FMECA of CNC machine tool design stage based on CBWM and DEA

Abstract In view of the problems that FMECA in the design stage of CNC machine tools does not take into account the complexity of the designed functional structure, does not compare the weight of risk factors, and is not easy to distinguish the harm degree of failure mode, CBWM, and DEA are applied to the study of FMECA in the design stage of CNC machine tools. Based on the complexity of functional structure in machine tool design, score the factors of each potential failure mode, form a decision unit, re‐formulate the scoring table, and subdivide the severity into machine tool hazard (M), personal hazard (P), environmental hazard (E), and buyer satisfaction (B). The factors influencing risk factors were defined as the probability of failure mode (O), machine tool hazard (M), personal hazard (P), environmental hazard (E), and buyer satisfaction (B). On the basis of the scoring of each factor, the functional structure complexity (C) is taken as the input index, and the risk factor is taken as the output index. The CBWM method is applied to determine the weight of each risk factor, and DEA method is used to calculate the efficiency of each decision making unit. Finally, a new method for calculating risk priority number RPN is proposed by integrating the score value of factors, weight value of factors, and efficiency value of fault mode, and the hazard degree of fault mode is ranked according to the risk priority coefficient. Taking a machining center spindle system as an example, the proposed method is applied to analyze the fault mode and its influence, and the effectiveness of the proposed method is verified.