In previous post, quantitative risk analysis techniques is started with hazard identification then frequency analysis. Frequency itself can be estimated by two approaches, which are generic data approach and modeling approach. The first approach is already described in previous post.
Modeling approach is used to estimate leak frequency when general statistics data is not available. Modeling approach use fault tree analysis or event tree analysis.
Fault Tree Analysis (FTA)
Fault Tree Analysis provide estimated frequency/likelihood of even for events that have never occurred by combining all possible basic failure mode (collision, dropped object, human error). These modes are combined and we tract how these initiating events can propagate to the top event by progressive failures of safeguard or by combining with other events. We use AND or OR gate. Read More