Bowtie Methodology: Barrier-Based Risk Management Training

What Is the Bowtie Methodology?

The Bowtie methodology is a barrier-based risk assessment method that shows, in a single diagram, how a hazard can lead to an unwanted event and what can be done to prevent it or limit its consequences. The diagram gets its name from its shape: the causes are drawn on the left, the consequences on the right, and the central “knot” is the moment when control over the hazard is lost.

Because it is visual and easy to understand, the Bowtie methodology is widely used in process safety, occupational health and safety, and major accident prevention. It helps technical teams, managers and operators share a common picture of the risks and of the barriers that keep them under control.

Main Elements of a Bowtie Diagram

Hazard: an activity, substance or condition with the potential to cause harm, such as a flammable liquid stored in a tank.
Top event: the moment control over the hazard is lost, for example a loss of containment.
Threats: possible causes that can lead to the top event, such as corrosion, overfilling or human error.
Consequences: possible outcomes of the top event, such as fire, explosion, injuries or environmental damage.
Preventive barriers: measures on the left side that stop threats from leading to the top event.
Mitigating barriers: measures on the right side that reduce the severity of the consequences.
Escalation factors: conditions that can make a barrier fail, together with the controls that protect the barrier.

Why Use the Bowtie Methodology?

The Bowtie methodology turns complex risk information into a clear picture. It makes it easier to see which barriers are critical, who is responsible for them and how their performance should be monitored. It also connects risk assessment with day-to-day operations, maintenance and training.

Bowtie diagrams can be built on the results of existing studies such as HAZOP or LOPA and kept up to date as part of management of change. They are also useful in incident investigations, where they help teams identify which barriers failed and why, and which improvements will have the greatest effect.

For establishments covered by the Seveso III Directive and the Turkish BEKRA Regulation, Bowtie diagrams can support the analysis of major accident scenarios in safety reports and major accident prevention documents. Learn more in our Seveso information training.

What Does the Bowtie Methodology Training Cover?

Our barrier-based risk management training explains the Bowtie methodology step by step, from defining the hazard and top event to evaluating barrier quality. Topics include:

Principles of barrier-based risk management
Building a Bowtie diagram: hazards, top events, threats and consequences
Identifying preventive and mitigating barriers and escalation factors
Assessing barrier effectiveness and assigning responsibilities
Using Bowtie results in process safety, Seveso documents and audits
Practical workshop exercises on example scenarios

Who Should Attend?

The Bowtie methodology training is designed for process safety and HSE specialists, plant and maintenance managers, environmental engineers, risk analysts and consultants. It is also useful for teams preparing major accident scenarios, reviewing the barriers in their existing risk assessments or looking for a clearer way to communicate risks to management and operators. Training dates are announced on request; contact us to receive the next schedule or to organise an in-house session for your company.

You can find our other programmes on the Doruksistem Trainings page.

Bowtie Methodology