FMECA‐Based Reliability Analysis of Heavy‐Duty CNC Machine Tools

ABSTRACT In view of the complex structure, difficulty in fault tracing, limited samples, and insufficient data in heavy‐duty computer numerical control (CNC) machine tools, the failure modes, effects, and criticality analysis (FMECA) is applied in the analysis of the reliability of the subsystems of heavy‐duty CNC machine tools. Combined with the structural characteristics of the machine tool, the operation status and other factors, the machine tool subsystem was divided, and the failure causes of the machine tool subsystem were analyzed using the FMECA method. Risk priority number (RPN) and quantitative criticality analysis (CA) were used to analyze the criticality degree of the subsystem. The distance function is used to assign weights, and the results of the two criticality analyses are combined to obtain an accurate subsystem criticality ranking, which reduces the subjectivity of expert scores and the impact of errors caused by small samples. The maintenance analysis of the machine tool subsystem is introduced, and the maintenance assessment of the subsystem is completed based on the criticality and maintainability and the reliability analysis of the heavy‐duty CNC machine tool is completed. The analysis results can provide a reference for enterprises to take targeted maintenance measures for different subsystems, accurately investing limited resources in the links that have the greatest impact on system reliability and balance safety, cost, and availability.