Bowtie analysis is a risk visualization method that puts one hazardous scenario on a single page: threats on the left, the loss-of-control moment (the top event) in the middle, consequences on the right, and the barriers standing on every path. Its power is communication: an operator, a manager, and an auditor can all see which defenses exist, what each one does, and what happens if it fails.
The three are stages of the same conversation. A HAZOP systematically finds the scenarios. LOPA quantifies whether specific scenarios have enough independent protection. The bowtie takes the scenarios that matter most and makes them visible and ownable: less rigorous than LOPA, far more communicable, and uniquely good at showing barrier health over time. Mature process safety programs use all three where each is strong.
Hazard: 5,000 liters of flammable solvent; top event: loss of containment during tanker transfer. Threats: hose failure (barriers: rated hoses on 12-month replacement, pre-use inspection), overfill (barriers: level control plus independent high-level trip, verified per SIS proof testing), drive-away (barriers: wheel chocks, interlocked coupling, keys surrendered). Consequences: pool fire (barriers: zoned electrics and grounding against ignition, bunding, foam response); vapor exposure (barriers: PPE, exclusion zone). Escalation factors: winter contractor drivers unfamiliar with site rules, controlled by induction and supervised first transfers. On one page, the site can answer the auditor’s only real question: which of these barriers would fail an inspection today?
A bowtie is a claim about defenses; maintenance is where the claim is tested. Every hardware barrier on the diagram, trips, relief devices, grounding, foam systems, hoses, maps to inspection and test tasks with intervals and evidence, and every degraded barrier is a live weakening of a specific line on a specific diagram. Sites that link the two stop discovering dead barriers during investigations.
Fabrico is not a bowtie drawing tool; safety teams build the diagrams. Fabrico keeps the barrier claims true: each hardware barrier’s tests and inspections run as scheduled work orders with completion evidence, overdue barrier maintenance is conspicuous, and asset history shows each barrier’s real reliability record when the diagram is reviewed. The bowtie says what defends the plant; the CMMS proves it still does. EU-built, with EU data residency.
Fewer than enthusiasm suggests: one per major accident hazard scenario, typically a handful to a few dozen for a serious site. The value is depth and ownership per diagram, not coverage statistics.
A barrier must be effective on its own, independent, and auditable, with an owner and a verifiable condition. "Operator vigilance" is not a barrier; a trained operator executing a specific detection-and-response task, with that competence maintained and checked, can be.
No. Any concentrated-energy scenario diagrams well: ammonia refrigeration, high-speed rotating equipment, warehouse fire, even machine access scenarios. If the plant has a handful of ways to have a very bad day, each one deserves a page.
Want every barrier on your bowties backed by scheduled, evidenced maintenance? Book a Fabrico demo to see barrier health live in a field-ready CMMS.
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