Fault detection and diagnosis (FDD) is crucial for dynamic
process
safety analysis. Integrated with failure prediction models, it enables
us to realize how a deviation in process variable(s) can affect system
safety (measured as risk). This work aims to overcome the challenges
of nonlinear, non-Gaussian, and multimodal behavior of the processing
systems to detect abnormal process operations, predict dynamic operational
risk, and diagnose root cause of the abnormal situation. A methodology
is proposed here by integrating different techniques. The artificial
neural network (ANN) is used to identify process modes, while the
Bayesian network (BN) is used for fault detection. How a fault will
lead to a process failure is modeled using the event tree (ET), whereas
time-dependent losses associated with the failure scenarios are assessed
using the inverted normal loss function (INLF). A probability adaption
mechanism is used to estimate the conditional probabilities in each
time slice. The complexity of estimating conditional probabilities
is handled using the copula theory. The proposed framework is validated
using numerical, simulated, and industrial datasets. The results suggest
that the developed framework can provide greater flexibility and wider
applications.