7-Fault Tree Analysis (FTA)
The fault tree (FTA — Fault Tree Analysis) starts from a top feared event and works recursively down to elementary causes via logic gates.
Structure
| Element | Description |
|---|---|
| Top event | The dangerous phenomenon being analysed |
| Intermediate events | Sub-causes or sub-systems |
| Basic events | Elementary causes (component failure, human error) with their probability |
| AND gate | All child events must occur simultaneously |
| OR gate | A single child event is enough |
Calculation
The probability of the top event is calculated from the probabilities of the basic events via the logic gates. Minimal cut sets are identified with the MOCUS algorithm.