Fig. 5
Calculation results of leaf node occurrence probabilities for multi-parameter monitors at different usage stages. This figure shows the prior probabilities of basic events (BE), intermediate events (M), and the top event (T) for multi-parameter monitors at three usage stages, calculated using the method in Sect. 2.4.1 (Forward Propagation: Prior Probability Calculation). Probabilities were derived from expert judgments based on original data collected in this study, calculated and visualized using the FAHP-FTA-BN framework and Netica (Version 7.01, Norsys Software Corp.). No external data or database was used. Panel A: Monitors (1–5 years). Panel B: Monitors (6–10 years). Panel C: Monitors (11–15 years). “Fault” indicates failure probability, and “Work” indicates normal operation probability. These results highlight failure trends across life-cycle stages, supporting targeted maintenance planning.
