Icologiq Knowledge · Method
Bowtie Analysis
A qualitative risk and barrier analysis method that maps threats leading to a loss-of-control event and the preventive and mitigating barriers used to stop or limit consequences.
Also known as:
Bow-tie analysis, Bow Tie Analysis, bowtie method, bow-tie method, bowtie diagram, bow tie risk assessment
At a glance
Type
Method
Topic
Process Safety
Applies to
Tank Terminals & Chemicals
Current version
Status
Recognised process-safety risk methodology
Last reviewed
September 30, 2026
Definition
Bowtie Analysis is a qualitative risk assessment and barrier management method that visualises a hazardous scenario around a loss-of-control or top event. Threats are shown on the left together with the preventive barriers intended to stop the top event from occurring. Consequences are shown on the right together with mitigating barriers intended to limit escalation or harm. The method makes the relationship between hazards, threats, consequences and critical controls visible so teams can discuss how risk is actually being managed.
Why it matters
For process-safety and major-hazard risks, protection rarely depends on a single safeguard. HSE and Operations managers need to know which barriers are critical, what each barrier is expected to do, who owns it and what could weaken its performance. Bowtie Analysis provides a shared model for making those dependencies visible and for deciding whether existing controls are sufficient. The same model can support Management of Change, audits and incident investigations by showing which controls may be affected by a change, which need assurance and which failed or were missing when an event occurred.
Clarify the hazardous source and the loss-of-control event that sits at the centre of the bowtie.
Define the hazard and Top Event
1
List the events or conditions that could cause the Top Event, using operational knowledge and incident experience.
Identify credible threats
2
Identify controls intended to stop each threat from progressing to the Top Event and avoid treating broad management activities as barriers without a clear function.
Map preventive barriers
3
Describe what can happen after the Top Event if escalation is not controlled.
Identify credible consequences
4
Identify controls intended to reduce the likelihood or severity of consequences after loss of control.
Map mitigating barriers
5
Define who owns critical barriers, what can degrade them and how their performance will be monitored through Barrier Management.
Assign ownership and assurance
6
Method explained
Building a useful bowtie model
Bowtie Analysis makes a risk scenario visible by connecting threats, a Top Event, consequences and the barriers intended to prevent or mitigate escalation. The model is strongest when barrier roles and degradation factors are specific enough to support ownership and assurance.
The systematic identification, ownership, monitoring and maintenance of risk controls that prevent hazardous events or mitigate their consequences.
Barrier Management
Process
· Process Safety
A systematic approach to preventing major incidents by managing hazards associated with hazardous processes, substances, equipment, procedures and organizational change.
Process Safety Management
Framework
· Process Safety
A structured assessment used to identify hazards or uncertainties, estimate their risk and determine whether controls or further action are required.
Risk Assessment
Process
· Risk
A structured process for evaluating and controlling safety, operational and compliance risks before significant technical, organizational or process changes are implemented.
Management of Change
Process
· Change/HSE
A structured process for establishing what happened in an incident, why it happened, which controls failed or were missing, and what actions can reduce the risk of recurrence.
Incident Investigation
Process
· CAPA & Incidents
Explore further
Related knowledge
Explore related standards, processes and quality-management concepts.
Relevant Icologiq capabilities
Explore the quality processes and platform capabilities connected to this topic.
In practice
Where this matters
See which industries and Icologiq capabilities are most closely connected to this topic.