Risk Evaluation and Application on Fuzzy-FMECA Method Using Cloud Model

In order to safeguard the safety of passengers and reduce maintenance costs, it is necessary to analyze and evaluate the security risk of the Railway Signal System. However, the conventional Fuzzy Analytical Hierarchy Process (FAHP) can not describe the fuzziness and randomness of the judgment, accurately, and once the fuzzy sets are described using subjection degree function, the concept of fuzziness will be no longer fuzzy. Thus Fuzzy-FMECA method based on cloud model is put forward. Failure Modes Effects and Criticality Analysis (FMECA) method is used to identify the risk and FAHP based on cloud model is used for determining the subjection degree function in fuzzy method, finally the group decision can be gained with the synthetically aggregated cloud model, the method’s feasibility and effectiveness are shown in the practical examples. Finally Fuzzy-FMECA based on cloud model and the conventional FAHP are used to assess the risk respectively, evaluation results show that the cloud model which is introduced into the risk assessment of Railway Signal System can realize the transition between precise value and quality value by combining the fuzziness and randomness and provide more abundant information than subjection degree function of the conventional FAHP