A new reliability allocation method for machine tools based on ITrFNs and AHP-GRA.

In the reliability optimization design field of CNC machine tools, reliability allocation plays a significant part, which has the characteristics of high complexity and strong uncertainty. Traditionally, reliability allocation methods have the disadvantages of a single allocation influence factor, too subjective or too objective, not flexible enough, etc. To solve the related problems, a novel reliability allocation method for machine tools is proposed, which combines subjective and objective weightings, and a variety of influencing factors are considered comprehensively. To deal with the characteristic of uncertainty and fuzziness in machine tool reliability analysis, different intuitionistic trapezoidal fuzzy numbers (ITrFNs) are allocated according to the importance of influencing factors. As the subjective method, the analytic hierarchy process (AHP) can reflect the decision maker's subjective preferences of machine tool influence factors, while the grey relational method (GRA) can analyze the relationship between data which is adopted as an objective weighting method. The reliability of each subsystem is obtained by combining the two methods. Finally, the validity of the proposed method is proved by an illustration analyzing and comparing it with the traditional AHP method and fuzzy allocation methods. [ABSTRACT FROM AUTHOR]