Risk evaluation method in failure mode and effects analysis based on failure cause-effect chain

Traditional risk evaluation method in Failure Mode and Effects Analysis(FMEA) did not consider development process of failure mode.There was no systematic risk evaluation analysis,and inconsistence in experts' evaluation in FMEA.In order to improve accuracy and applicability of risk valuation in FMEA,the concept of failure cause-effect chain was introduced which was regarded as risk evaluation objects.Concrete meanings of each index used in Risk Priority Number(RPN) were defined.RPN calculation formula was modified,systematic evaluation were conducted on risk of components and product.According to the facts that experts tended to present multi-granularity linguistic evaluation information,basic linguistic terms set was used to uniformly input evaluation information,then depended uncertain ordered weighted averaging operator was used to aggregate evaluation information.Finally,decision-making process of selecting maintenance strategies of mechanical diaphragm metering pump was used as a case to illustrate the effectiveness and practicality of the proposed method.