Research On FMEA Method Based On Improved Fuzzy TOPSIS

As the ocean structure becomes larger and more complex,it is necessary to carry out risk analysis to ensure system safety.There are some methods for risk analysis,from the point of view of accuracy,it can be divided into qualitative analysis and quantitative analysis methods.Failure Mode and Effect Analysis(FMEA)is often used as qualitative methods in risk identification.Although FMEA is simple and easy to use,there are many deficiencies for this method.For example,the same Risk Priority Number(RPN)may appears in the risk priority ranking process,making it impossible to distinguish the priority of risk.Through subjective experience,risk factors which are Occurrence,Severity are Detection are rated with specific values that do not fit in with the facts.The relative weight of risk factors are ignored in risk priority ranking,etc..Through research on FMEA method shortcomings,fuzzy evidence reasoning and comprehensive weighting are introduced in this paper to improve the ratings and relative weights of risk factors to get fuzzy TOPSIS improved.When fuzzy TOPSIS improved is used to prioritize the risk of failure modes,a more reliable reference is offered for risk decision-makers in risk identification.The main contents are as follows:(1)Aiming at the shortcomings of FMEA,scholars have put forward some methods to improve it.Fuzzy rule base and fuzzy TOPSIS are the most typical methods among them.As FMEA,fuzzy rule base and fuzzy TOPSIS are often used in risk prioritization,the ranking results of these three methods are compared by using a classical example to find a more reasonable and effective risk priority ranking method.Comparative analysis shows that fuzzy TOPSIS is more reasonable and effective.(2)The fuzzy TOPSIS method still has some shortcomings.For example,the uncertainties and incompleteness of the evaluation information are not dealt well.Although the weights of risk factors are considered,only the subjective weights are taken into consideration without Objective weight,etc..By introducing the fuzzy evidence reasoning and the comprehensive weighting method,fuzzy evidence reasoning is used to represent the rating information of risk factors in fuzzy confidence structure and assigns different confidence levels to different ratings information.Through comprehensive weighting thought,subjective weights and objective weights of risk factors are comprehensively weighted.Finally,an example is given to verify the rationality and validity of the improved fuzzy TOPSIS.