Build bowtie risk diagrams that engineers actually use.
A fast, modern editor for top events, threats, preventive and recovery barriers, escalation factors, and consequences. Free in your browser. Native on your desktop.
Used by engineers in process safety, aviation SMS, cybersecurity, medical devices, and reliability.
What is a bowtie diagram?
A bowtie diagram puts a single top event in the centre. To the left, threats that could cause it, separated by preventive barriers. To the right, consequences that could follow, separated by recovery barriers. Escalation factors capture the conditions that defeat barriers. The result is a single picture that explains a hazard, the things that mitigate it, and the things that erode those mitigations — in a form that an engineer, an auditor, and a manager can all read.
Built for the way bowties actually get drawn
Every feature exists because someone needed it during a real workshop, audit, or review.
Visual editor
Drag, connect, and label nodes. Built on a graph engine that scales to large diagrams without slowing down.
Threat & consequence arms
Model multiple threats and consequences per top event with clean alignment and auto-layout helpers.
Barrier modelling
Preventive and recovery barriers as first-class objects, with type, owner, and effectiveness annotations.
Escalation factors
Capture the conditions that degrade a barrier and the secondary controls that defend against them.
Export anywhere
PNG and SVG for reports and slides. JSON for version control, code review, and integration with other tools.
Browser & desktop
Free in any modern browser, plus signed native apps for macOS, Windows, and Linux. No account required.
Used across engineering disciplines
The same diagram language; very different worlds.
Process Safety
Visualise major-accident hazards alongside LOPA studies. Communicate ALARP to operations, management, and regulators in a single diagram.
Aviation Safety Management
Map incidents to threats and controls in line with ICAO SMS expectations. Share findings across flight ops, engineering, and ground handling.
Cybersecurity
Model threats to assets and the technical and procedural controls that mitigate them. Useful in tabletop exercises and post-incident reviews.
Medical Devices
Complement ISO 14971 risk files with a visual view of hazards, sequences of events, and risk controls.
Reliability & Asset Integrity
Pair with FMEA and fault-tree analysis to communicate failure modes and the inspection/maintenance regime that keeps them in check.
Frequently asked
What is bowtie risk analysis?
Bowtie analysis is a visual risk-assessment technique. A top event sits in the centre. Threats that can cause it sit to the left, separated by preventive barriers. Consequences that can follow sit to the right, separated by recovery barriers. The shape resembles a bowtie — hence the name.
Is Bowtie Risk Engine free?
Yes. The browser app and the desktop apps for macOS, Windows, and Linux are free, with no sign-up required.
Can I use it offline?
The desktop apps run fully offline. Diagrams can be saved to disk and exported locally.
What can I export?
PNG, SVG, and JSON. Use SVG for reports and slides, and JSON for version control or integration with other tools.
Open the editor and draw your first bowtie.
Free. No sign-up. Runs in any modern browser.