Failure Mode and Effects Analysis Method on the Air System of an Aircraft Turbofan Engine in Multi-Criteria Open Group Decision-Making Environment

Failure mode and effects analysis (FMEA), an proactive risk management approach, has been widely applied in a variety of industries, especially in aircraft industry. In the process of implementation, the influence and uncertainty among different experts is inevitable. In order to handle the uncertainty in the assessments of FMEA experts, Dempster-Shafer evidence theory was introduced to FMEA for its flexibility and superiority in coping with uncertain and subjective assessments. However, traditional Dempster combination rule have difficulty in dealing with highly conflicting evidence that given from FMEA experts’ assessments. Moreover, experts themselves may influence each other though process such as chatting, judging, decision-making and voting. In this paper, we explore the problem of conflict evidence fusion from a correlation perspective among FMEA experts. We use ambiguity measure and Gaussian distribution to deal with the highly conflicting evidence. We use ambiguity measure to calculate the variance of Gaussian distribution. Then, we use Gaussian model to generalize expert assessments. After that, we use Dempster combination rule to fuze assessments from different experts. Finally, we calculate the risk priority number to rank the risk level of the FMEA items. The experiment results in the air system of an aircraft turbofan engine shows the efficiency and accuracy of the proposed method.