Fault Tree Analysis

Quick start

Add an OR or AND gate. This becomes your top event.
Add more gates for any intermediate events.
Add Basic Events for the leaves, then use Connect to wire them up.
Press Calculate to get the top event probability and cut sets.

Properties

Select a node to edit its properties.

Name Description (optional)

Model

Failure rate λ (per hour) Mission / exposure time T (hours) Failure probability q Failure on demand γ Repair rate μ (per hour) Mean time to repair MTTR (hours) Proof-test interval τ (hours) Condition onset rate f (per hour) Mean duration d (hours)

Reference (optional)

No results yet. Build a tree and press Calculate.

All basic events in the current tree. Edit any cell directly. Changes apply to the canvas immediately.

No basic events on the canvas yet.

Notes on this tree (assumptions, references, anything worth passing along). Saved and shared along with the tree.

Minimal cut sets

Importance measures

Frequency contributions