Fault tree analysis using evidence theory and evidential networks With imprecise expert knowledge

Fault tree analysis (FTA) is a popular methodology for system reliability analysis. The occurrence probability of the basic event is accurate in traditional fault tree (FT). Owe to the lack of the reliability data, especially in early design stage; a large amount of uncertainties may be included in FTA. In this study, the Dempster-Shafer (D-S) evidence theory is employed to quantify the uncertainty of the FTA and to aggregate the different evaluation information of multiple experts on the occurrence probability of basic event. The evidential network (EN) is used to propagate the uncertainty in FTA. The FT of the aero-engine damage caused by low pressure of lubricating oil is analyzed.