Bowtie risk
The barrier-based risk diagram used in process safety, aviation and healthcare: threats on the left, the top event at the knot, consequences on the right, and preventive and recovery barriers on every path — each with its own effectiveness, escalation factors and degradation controls. Residual risk per path is computed from the barrier chain, so a decorative barrier is visible as one that changes no number.
In the same space
Most users come to Bowtie risk from CGE BowTieXP, Wolters Kluwer Bowtie or Visio bowtie drawings. flowss runs this engine in the browser — no install, shareable via URL, exportable to PNG / SVG / PDF / source.
Syntax at a glance
top "Loss of containment"
threat "Corrosion" likelihood: 0.1 {
barrier "Inspection" effectiveness: 0.8
}
consequence "Explosion" severity: 5 {
barrier "Gas detection" effectiveness: 0.85
}Paste this in the Studio code pane to see Bowtie risk render live. The full grammar is at the upstream-docs link above.
Sample templates
All 13 →COMAH-style bowtie for a 68-tonne LPG bullet: 0.43 loss-of-containment opportunities a year cut to a 0.0231/yr top event, ranking the independent high-level fill trip as the most critical barrier on site and flagging its proof-test bypass as an unmanaged escalation factor.
Ward-level bowtie for injectable medicines: 60 dosing errors a year reduced to 5.04 wrong doses reaching a patient, ranking the bedside barcode scan twice as critical as the smart-pump drug library and leaving 97.9% of the inherent harm removed.
Aerodrome safety bowtie covering pilot, driver and controller threats: 6.8 incursion opportunities a year cut to 0.43/yr on the runway, ranking illuminated stop bars above surface movement radar and the go-around above every other recovery barrier.
Offshore DROPS bowtie for tools and tubulars handled 30 m above the drill floor, turning 3.65 release opportunities a year into 0.353/yr of falling objects and ranking the tool-tethering policy above every inspection regime on the rig.
Cyber bowtie treating ransomware as a barrier problem rather than a tooling problem: 48 attempts a year reduced to 1.51 executions, ranking phishing-resistant MFA three times above the mail gateway and flagging an appliance missing from the asset inventory.
Food-safety bowtie for ready-to-eat product handled after the cook step, turning 14.5 contamination opportunities a year into 1.49 that get past the lethality step, ranking the physical high-care barrier above all environmental monitoring.
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