Research On Application Of Fuzzy-FMEA In Marine Traffic Safety Evaluation

Safety is not only the most important issue in the domain of marine,but also the ultimate requirement for all kinds of ships.The Qiongzhou Strait is the key water area that links Hainan Island and mainland.And lots of marine accidents happen in that strait in those years.In order to ensure the safety of maritime traffic,reduce the loss of life and property at sea and the pollution of the sea,this thesis uses fuzzy failure mode and effect analysis(FMEA)to evaluate the ship collision risk of Qiongzhou Strait,hoping that it can put forward some countermeasures and suggestions for reducing the collision accidents,and provide the basis for the related research of Formal Safety Assessment.Firstly,this thesis studies the basic situation of the Qiongzhou Strait,and sum up the accidents in the Qiongzhou Strait,proposing that the study should focus on the risk of ship collision.It explains the basic theory of the Formal Safety Assessment(FSA)and the fuzzy mathematics.And it introduces the FMEA method in detail.Secondly,the establishing mechanism of Fuzzy-FMEA model are introduced,including the use of the traditional FMEA method,the establishment of fuzzy term set and membership function,fuzzy rule base and fuzzy inference,and the method of defuzzification.Thirdly,as an example,the Fuzzy-FMEA model is applied to the evaluation of ship collision risk in the Qiongzhou Strait.In this process,it should explore the scenarios based on the experiences and other data.And then,it comes to establish the FMEA table,calculate the crisp risk priority number(RPN)of each scenario by dealing with the results of the questionnaires,so as to get the rankings of the criticality of each failure.The results of the calculation of the fuzzy RPN are more precise by pulling in the fuzzy logic.The Fuzzy-FMEA used in this thesis mainly focuses on the risk factors of FMEA.The three factors are difficult to estimate precisely.Much of the information in FMEA is expressed linguistically in terms.What's more,the final measure is just a simple product.But for different circumstances,this product can't always reflect the risk ranking of failure modes well.To improve the rationality and accuracy of the risk rankings of the traditional FMEA,this quantitative algorithm is very helpful.This thesis gets the final risk rankings of each scenario by comparing the fuzzy RPN,and obtains the conclusion:"human error in general" has the highest risk number,while "failure of machinery or electrical system" has the lowest.In order to reduce the risk of collision,it should focus on the human factors,as well as several encounter situations of navigation.Finally,this thesis gives out some advice about the scenarios which deserve more attention,for the administration,shipping companies,and seafarers.