#QRA

Modern fire-safety engineer's office at golden hour with a wall-mounted F-N curve chart — red intolerable zone above a downward-sloping diagonal, amber ALARP carpet in the middle, green broadly acceptable zone below, dotted plant curve descending through the carpet — and an engineer's hand pointing at the chart with a red marker

📈 Fire Risk Assessment May 8, 2026 · 11 min read

F-N Curve and Societal Risk: Drawing the Line on Safety

An F-N curve maps the societal risk a regulator will tolerate. Here is the math, the slope, the ALARP carpet, and where each sector draws the line.

Bow-tie risk diagram for fire — blue fault tree of causes converging into a central flame, and an orange event tree branching outward into five outcomes

📈 Fire Risk Assessment April 18, 2026 · 7 min read

Event Tree vs Fault Tree: Picking the Right Fire Tool

Event tree vs fault tree: one tracks causes backward, the other tracks outcomes forward. Here is how fire engineers pick the right one.