In high-risk industries, a single overlooked hazard can lead to catastrophic incidents.
Whether it’s an oil spill off the coast, a chemical release in a manufacturing plant, or a mining accident in northern Ontario, the consequences of poor hazard management are serious—and often preventable.
That’s where the Bowtie Method in incident investigation comes in.
This visual risk assessment tool helps teams understand how hazards can escalate into major events and what barriers are (or should be) in place to prevent them.
It gets its name from the shape of the diagram: on one side, potential causes; on the other, potential outcomes—with a central event in the middle.
The visual format makes it easier for workers, safety professionals, and decision-makers to clearly see the relationships between causes, controls, and consequences.
More Canadian industries—from energy and transportation to construction and healthcare—are using the Bowtie Method as part of incident investigation training to improve hazard awareness, strengthen risk controls, and reduce repeat events.
According to the Canadian Labour Congress, there were over 348,747 lost-time injuries in 2022—many of which could have been mitigated with better hazard recognition and planning.
In this blog, we’ll explain how the Bowtie Method works, explore its structure, highlight real-world applications, and show how it can enhance your workplace’s investigation training program.
What is the Bowtie Method of Incident Investigation?
The Bowtie Method is a barrier-based risk management technique designed to help teams visualize how incidents occur and how they can be prevented.
It gets its name from the way the diagram resembles a bowtie: the knot in the middle represents the top event—the moment when control is lost, such as a leak or equipment failure.
On the left side, the diagram shows all the threats or causes that could lead to the top event (e.g., human error, equipment malfunction, or external events).
Each threat is linked to the central event by a series of preventive barriers—these are the controls put in place to stop that threat from causing the top event, such as maintenance checks, training, or safety systems.
On the right side, the bowtie lays out the potential consequences that could follow if the top event occurs (e.g., fire, environmental release, or injury).
Between the top event and each consequence, the diagram shows mitigation barriers—actions or equipment that reduce the severity of those outcomes, like emergency shutdown procedures, fire suppression systems, or rescue plans.
Originally developed in high‑hazard industries like oil & gas, aviation, and chemicals, the Bowtie Method has gained traction in occupational safety training across Canada. It helps safety teams and workers alike understand complex risk scenarios at a glance and identify where controls might be missing or need strengthening.
By laying out threats, barriers, the top event, and consequences all in one picture, organizations can more effectively investigate past incidents and build training programs that prevent future ones.
The Bowtie Analysis Process Step-by-Step
The Bowtie Method breaks down the complexity of incident risk into a clear and structured visual framework. It's not just about drawing diagrams—it’s about understanding how incidents happen and how they can be prevented.
Whether you're preparing for a risk assessment or investigating a past event, the bowtie diagram helps teams pinpoint exactly where controls exist and where gaps may lie.
This method is particularly effective in training environments because it’s easy to understand and highly adaptable across industries.
Each step of the process builds toward a complete picture of the risk scenario, showing how threats can escalate into major events and what can be done to stop or control them. Below, we walk through the major steps involved in building a bowtie analysis.
1. Define the Top Event
Every bowtie diagram starts with identifying the top event—the central point of failure you’re trying to prevent or understand.
In incident investigation, this could be a moment when control is lost, such as a chemical leak, equipment collapse, or worker fall. It is not the cause or the consequence—it’s the turning point.
Clearly defining the top event is crucial because the entire diagram is built around it. A poorly defined top event can confuse threats and consequences or make it harder to identify relevant controls.
For example, in a confined space entry incident, the top event might be “loss of breathable atmosphere” rather than “worker collapse” or “gas leak.” This allows for a clearer mapping of both what can cause the event and what happens after.
To define your top event:
- Use specific and observable language.
- Make sure it represents a loss of control, not just an outcome.
- Keep it neutral—avoid terms that imply blame.
Once defined, the top event becomes the “knot” of your bowtie—everything else flows into or out from this point.
2. Identify Threats
On the left side of the diagram, you’ll list all the threats—these are the direct causes that could lead to the top event.
Threats might be technical (e.g., equipment wear), human (e.g., improper operation), or environmental (e.g., weather conditions). The goal is to identify what might go wrong that could trigger the incident.
Each threat should be paired with preventive barriers—controls or safeguards in place to stop that threat from causing the top event. For example, if a threat is “valve left open,” a barrier might be a pre-entry checklist or automated valve alarm.
To identify threats effectively:
- Review historical incidents and near misses.
- Conduct interviews with operators and safety staff.
- Analyze job hazard assessments and process flows.
Common threats vary by industry, but across Canadian workplaces, human error and equipment failure remain top contributors to workplace incidents.
By identifying and understanding threats clearly, teams can take proactive steps to reinforce controls and reduce risk—before the top event ever occurs.
3. Identify Consequences
Once you’ve outlined the threats leading to the top event, the next step is to map the consequences—what could happen if the top event occurs.
These are shown on the right side of the bowtie diagram and represent the possible impacts on people, the environment, operations, or property.
Consequences can range from minor injuries to catastrophic failures depending on the nature of the top event.
For instance, if the top event is “loss of containment” in a chemical plant, consequences might include worker exposure to hazardous chemicals, environmental contamination, or production shutdown.
To identify consequences effectively:
- Consider direct and indirect outcomes (e.g., injury, legal penalties, public reputation damage).
- Use real incident data from your workplace or industry.
- Think about short-term and long-term impacts.
In Canada, organizations are increasingly required to report and analyze such outcomes under provincial Occupational Health and Safety (OHS) regulations, especially if injuries, fatalities, or environmental releases occur.
Understanding the full spectrum of possible consequences helps drive more informed risk management and resource allocation.
4. Add Preventive Barriers
Preventive barriers are the controls placed between each threat and the top event to stop the incident from occurring. These are placed on the left side of the diagram next to their corresponding threat.
Examples of preventive barriers include:
Each barrier should be evaluated not just for existence, but for effectiveness. A common issue in many workplaces is relying on administrative controls without verifying whether they’re consistently followed.
For example, if a threat is “improper forklift use,” and the only barrier is “forklift training,” you’ll need to assess how that training is delivered, refreshed, and monitored.
Preventive barriers are your first line of defence—they work to eliminate or reduce the chance of the top event happening at all.
5. Add Mitigating Barriers
Mitigating barriers are added to the right side of the diagram to minimize the impact of the top event after it occurs. These barriers do not stop the event itself but reduce the harm it causes.
Examples of mitigating barriers include:
Let’s say your top event is a flammable gas leak. Even with the best preventive barriers, leaks can still happen. A mitigating barrier might be a well-ventilated area or a gas detector alarm that ensures people evacuate before exposure.
When identifying mitigating barriers:
- Think about who or what is affected and how quickly a response must happen.
- Consider worst-case scenarios and how your systems would hold up.
- Evaluate if barriers are independent and not reliant on the same system that failed.
This part of the diagram reinforces the importance of layered safety. Even if one system fails, others can help minimize the outcome—potentially saving lives.
6. Test & Validate the Diagram
Once the bowtie diagram is complete, it's time to test and validate it. This step ensures the diagram reflects real operational conditions and hasn't missed any major threats or weak spots.
It also helps promote team alignment and shared understanding of the risks.
Validation should include:
- Stakeholder involvement: Gather input from operators, supervisors, safety professionals, and even contractors.
- Site walkthroughs: Compare the diagram to real-world processes.
- Simulation or tabletop exercises: Use hypothetical scenarios to test how well the barriers hold up under pressure.
- Cross-checking with incident reports: Make sure past incidents are reflected in the threats and consequences.
In Canada, industries like mining and energy often perform formal risk reviews that include bowtie validation. Tools like CSA Z1006 (for confined spaces) or ISO 45001 (for occupational safety) recommend involving multidisciplinary teams to capture all relevant controls.
Validating the diagram doesn’t just refine your analysis—it also builds trust and shared accountability across the organization. It confirms whether your controls are real, reliable, and ready when needed.
Why Use the Bowtie Method in Incident Investigation Training?
The Bowtie Method has gained recognition not just for risk analysis but also as an effective training tool in incident investigation training programs.
Unlike traditional methods that rely heavily on text-based reports or static checklists, the Bowtie Method provides a visual, interactive representation of risk—helping teams see the whole picture at a glance.
In training environments, this method helps learners grasp how hazards, causes, and consequences are connected, and how control measures work to prevent incidents.
It goes beyond theory by actively engaging participants in the process of identifying threats and evaluating safeguards.
Using the Bowtie Method in training builds awareness, reinforces procedures, and helps workers recognize how their actions tie directly into workplace safety.
It’s particularly useful in high-risk industries such as oil and gas, utilities, construction, and transportation—sectors where a single oversight can lead to serious consequences.
Visual Learning: Trainees Can Better Understand Complex Risks Through Visualization
One of the biggest advantages of using the Bowtie Method in training is its ability to simplify complex information through visualization.
Traditional incident investigation models—like root cause analysis or fault trees—often overwhelm learners with technical language and linear thinking. The Bowtie Method, on the other hand, presents everything in a clear, digestible format.
- Here’s how it works: At the centre of the diagram is the "top event"—the incident you're trying to prevent or analyze (e.g., chemical spill, fall from height). On the left side, you map out the threats or causes that could lead to this event.
On the right side, you show the consequences if it happens. Preventive and mitigating barriers are placed accordingly, creating a visual "bowtie" shape that immediately shows the logic of your safety system.
In a training session, this layout helps participants visually connect the dots between day-to-day tasks, potential hazards, and protective controls.
For example, a trainee in a confined space awareness training program can clearly see how failing to monitor gas levels (a threat) could lead to oxygen deficiency (top event), which might then result in unconsciousness or fatality (consequences)—unless certain barriers are in place.
Encourages Critical Thinking: Helps Learners Analyze Cause-and-Effect Relationships
One of the key strengths of the Bowtie Method is how it nurtures critical thinking among trainees. Rather than simply memorizing rules or compliance checklists, learners are encouraged to evaluate the relationship between actions, hazards, and outcomes.
When building a bowtie diagram, trainees must ask themselves:
- What could cause this event?
- What barriers are in place to stop it?
- What might happen if it occurs?
- How effective are the controls?
This exercise trains individuals to think systematically—they learn that incidents don’t happen in isolation.
For example, in a manufacturing setting, a trainee might identify “machine guard removal” as a threat. They’ll then think through what barriers are missing or failing (e.g., training gaps, weak enforcement), and what could result if nothing changes.
In a Canadian context—especially in high-risk environments like mining, energy, and forestry—critical thinking is an essential competency. Workers are often required to make real-time decisions about hazard controls.
Using Bowtie Method in incident investigation training equips them with a framework to evaluate risks and solutions independently, making them safer and more accountable on the job.
Supports Proactive Thinking: Focus is on Prevention and Mitigation—Not Just Fault-Finding
Traditional incident investigations tend to focus on what went wrong—assigning blame or pinpointing a root cause after the fact. The Bowtie Method shifts the perspective toward proactive prevention and control.
It’s not about who’s at fault—it’s about what systems failed and how they can be improved.
By exploring threats (on the left side of the bowtie) and consequences (on the right), trainees see that each step of an incident has warning signs and opportunities to intervene.
The method helps them identify weak points before an incident happens, making it a powerful tool in risk prevention training.
Improves Risk Awareness: Encourages Discussion Around Weak Points in Existing Barriers
Risk awareness is essential to workplace safety, but it’s not always easy to teach. The Bowtie Method excels at bringing risks to life and encouraging open discussion.
When trainees map out threats, consequences, and controls, they begin to see which barriers are strong, which are weak, and which are missing entirely.
For example, during a training session for confined space entry, participants might notice that while gas monitors are in place (a barrier), the team isn’t regularly reviewing calibration logs. That gap becomes clear in the visual diagram—and prompts discussion about improvements.
This method turns abstract risks into visible, understandable insights, prompting valuable conversations like:
- Are our controls truly effective?
- Do we rely too heavily on a single barrier?
- What happens if this one system fails?
Enhances Communication: Ideal for Cross-Functional Safety Teams and New Employees
Safety isn’t just the responsibility of supervisors or specialists—it’s a team effort. The Bowtie Method supports clear, collaborative communication by giving everyone a shared visual reference. It breaks down silos between departments, roles, and experience levels.
When a team sees a completed bowtie diagram, they can instantly understand the big picture:
- What went wrong?
- What could go wrong?
- What’s being done about it?
That kind of clarity is especially helpful for cross-functional safety teams, who may not always speak the same “technical language.”
It’s also a great onboarding tool for new employees. Instead of overwhelming them with long SOPs or dense investigation reports, employers can use bowtie diagrams to quickly explain:
- What hazards exist in this task?
- What are the key preventive controls?
- What happens if things go wrong?
This kind of clarity is invaluable in Canadian industries with diverse teams, rotating staff, and multilingual workforces. It supports compliance with training standards and helps build a shared understanding of safety responsibilities.
Bowtie Method vs. Traditional Investigation Tools
When it comes to understanding workplace incidents, safety professionals have several tools at their disposal. Two of the most common traditional methods are Root Cause Analysis (RCA) and Fishbone Diagrams.
While these tools are valuable, the Bowtie Method offers some unique advantages—especially for organizations that want to go beyond identifying what went wrong and focus more on preventing incidents altogether.
Visual and Intuitive
One of the most significant differences is the visual structure. The Bowtie Method uses a simple but powerful graphic that clearly shows the relationship between hazards, the incident itself (known as the “top event”), and the potential consequences.
It also displays the barriers on both sides: those that prevent the incident and those that mitigate the damage if it occurs.
In contrast, RCA or Fishbone Diagrams can be more text-heavy and analytical, which may make them harder to understand for non-technical team members or frontline workers.
Prevention-Focused
Traditional RCA is often conducted after an incident to uncover what failed and why. It tends to focus on assigning root causes—sometimes leading to a fault-finding mindset.
While useful, RCA doesn’t always explore what could go wrong next or whether safeguards are truly effective.
The Bowtie Method, on the other hand, works both before and after an incident. It can be used proactively to assess potential threats and weaknesses, or retroactively to understand where barriers failed.
This flexibility makes it especially useful in high-risk industries like oil and gas, aviation, utilities, and construction—sectors where one mistake can have life-threatening consequences.
Ideal for Complex Systems
Another strength of the Bowtie Method is its ability to handle complex systems.
In environments where multiple threats can lead to the same top event, and where there are layers of preventive and mitigation barriers, the bowtie diagram helps untangle that complexity in a way that’s easy to communicate across teams.
For Canadian workplaces striving to meet CSA standards or COR certification, the Bowtie Method offers a more comprehensive and proactive approach to incident investigation training.
It aligns well with modern safety management systems that emphasize prevention, transparency, and collaboration.
Applications of the Bowtie Method in Incident Investigation
The Bowtie Method is not just a theoretical model—it’s a practical tool being used in multiple high-risk industries across Canada and worldwide.
Its simple, visual layout makes it easier to understand how hazards can escalate into incidents and what controls are in place to stop them. More importantly, it helps identify where those controls might be weak or missing altogether.
Below are examples of how various industries apply the Bowtie Method in real-world incident investigation and risk management.
1. Oil & Gas – Identifying Explosion Risks and Preventive Barriers
The oil and gas industry is one of the earliest adopters of the Bowtie Method, due to the catastrophic potential of explosions, fires, and toxic gas releases. A top event might be a gas leak at a drilling rig.
On the left side of the bowtie, you would find threats such as equipment failure, corrosion, or human error. Preventive barriers might include pressure relief valves, regular maintenance schedules, and gas detection systems.
On the right, consequences could range from environmental damage to worker fatalities. Mitigating barriers could include emergency shutdown systems, fire suppression equipment, and evacuation protocols.
Using the Bowtie model in this setting allows operators to visualize risk scenarios and improve safety protocols proactively.
2. Chemical Plants – Mapping Hazardous Leaks and Mitigation Controls
Chemical facilities often deal with toxic, flammable, or reactive substances, making the Bowtie Method especially relevant.
A common top event could be a hazardous chemical spill. Threats may include tank overfilling, pipe corrosion, or valve malfunction.
Preventive barriers might include flow control systems, high-level alarms, and training in chemical handling. Mitigation could involve secondary containment, PPE (personal protective equipment), and emergency response teams.
The bowtie helps safety teams see how failures can occur, how to prevent them, and how to respond if they do.
3. Construction – Training for Fall Protection and Equipment Failure Risks
In construction, incidents involving falls from height or equipment malfunction are common and often fatal. A top event might be a worker falling from scaffolding. Threats might include missing guardrails, improper harness use, or unstable structures.
Preventive barriers would include proper PPE use, regular site inspections, and training in working at heights. If the fall occurs, mitigation might involve fall arrest systems or quick medical response.
The Bowtie Method is often used during safety orientations and toolbox talks to educate crews on how hazards translate into risks and the importance of controls.
4. Manufacturing – Managing Electrical Hazards and Process Malfunctions
Manufacturing environments are full of moving parts, high voltages, and automated systems—any of which can fail.
A top event might be an electrical fire caused by overloaded circuits. Threats include faulty wiring, lack of maintenance, or unauthorized modifications.
Preventive measures would include circuit breakers, thermal imaging checks, and staff training.
On the mitigation side, having fire extinguishers, suppression systems, and shutdown protocols can help reduce the impact. Bowtie diagrams can be built into lockout/tagout (LOTO) training and maintenance planning.
The Bowtie Method brings immense value to incident investigation by making hazards, controls, and consequences visible and easy to understand.
In Canada, more organizations across sectors are adopting this method to align with their due diligence obligations and improve the effectiveness of their safety programs.
Tools and Software for Bowtie Analysis
The effectiveness of the Bowtie Method often depends on the tools used to apply it. While you can sketch a bowtie diagram by hand or in a spreadsheet, dedicated software makes it much easier to manage, visualize, and share complex risk scenarios—especially in training environments.
These tools help trainers and safety teams simulate real-world incidents, document barriers, and collaborate across departments. Below are some of the most popular Bowtie software solutions used in Canadian workplaces.
BowTieXP by CGE Risk is one of the most widely recognized platforms for performing bowtie analysis. It’s especially popular in high-hazard industries like oil & gas, aviation, and manufacturing.
Key Features
- Interactive bowtie diagrams with easy drag-and-drop functionality
- Support for linking threats and barriers to safety management systems
- Built-in reporting tools
- Integration with incident databases and audit systems
Training Benefits
- Offers simulation features to test barrier effectiveness
- Used in workshops to create real-time visual learning experiences
- Facilitates hazard-awareness training by mapping company-specific risks
Enablon Bowtie Module
Enablon, part of Wolters Kluwer, offers a Bowtie module as part of its wider EHS and risk management suite. It's ideal for larger organizations looking to integrate bowtie analysis into broader compliance and incident management systems.
Key Features
- Customizable templates for various risk scenarios
- Automated alerts and compliance tracking
- Cloud-based collaboration and access control
Training Benefits
- Useful in classroom or remote settings thanks to real-time access
- Supports embedded training simulations and interactive walkthroughs
- Integrates with learning management systems (LMS)
Presight is a newer, cloud-based tool developed in Canada that focuses heavily on ease of use and accessibility. It's great for organizations new to bowtie methodology or those wanting to integrate it with broader operational risk tools.
- Key Features
- Intuitive interface with real-time collaboration
- Cloud storage and access for team-based projects
- Reporting dashboards for barrier effectiveness
Training Benefits
- Enables multiple users to work on the same diagram
- Trainers can create shared libraries of hazards and controls
- Excellent for simulating hypothetical events and encouraging group discussion
For teams looking for a lightweight, budget-friendly option, visual diagramming tools like Lucidchart or Miro can be used to create simple bowtie diagrams manually.
Key Features
- Easy-to-use drag-and-drop shapes
- Cloud-based access and version control
- Real-time collaboration and commenting
Training Benefits
- Useful for introductory training or workshops
- Encourages team brainstorming sessions
- Good for visual learners and group exercises
Whether you’re a safety trainer, a supervisor, or part of a compliance team, choosing the right bowtie software can help you strengthen your incident investigation training and improve risk communication.
Common Pitfalls to Avoid in Bowtie Training
While the Bowtie Method is a powerful tool for visualizing risk and improving safety outcomes, it's only as effective as the way it's implemented.
In training environments—especially where the goal is to teach workers or supervisors how to think critically about risk—it’s important to avoid a few common mistakes that can undermine the value of the method.
Below are four key pitfalls to watch for when using the Bowtie Method in incident investigation training.
Overcomplicating the Diagram with Too Many Threats
One of the most common errors is trying to include every possible scenario or hazard in a single diagram.
While it's tempting to be thorough, an overloaded bowtie can become confusing and lose its educational value. In training sessions, this can overwhelm participants and distract from the key learning objectives.
A better approach is to start with a focused scenario—like a fall from height or a gas leak—and build the diagram step-by-step. This keeps the discussion clear and helps trainees understand how to prioritize risks.
Treating Barriers as Static, Not Needing Validation
Another frequent mistake is assuming that just because a barrier exists, it’s effective. Barriers like PPE, procedures, or alarms can degrade over time or be improperly used.
In training, it’s essential to emphasize that barriers need regular testing, maintenance, and validation.
For example, using a gas detector is only useful if it's been calibrated and the worker knows how to interpret its readings. This mindset encourages a culture of active risk management rather than passive compliance.
Not Involving the Workforce in Identifying Controls
The Bowtie Method works best when it reflects the real conditions workers face—not just what’s written in policy manuals.
A top-down approach to building bowtie diagrams often misses practical insights that front-line staff can provide.
Training should involve open discussion, where workers contribute to identifying threats and barriers. This not only improves the accuracy of the diagram but also strengthens engagement and ownership of safety responsibilities.
Using the Diagram Only as a Compliance Exercise
The Bowtie Method shouldn’t be treated as a box-checking task. If the diagram is created and filed away without ongoing review or application, it loses its purpose. In training, it's important to stress that bowtie diagrams are living documents.
They should evolve with operational changes, incident learnings, and feedback from workers. When used actively, they can drive better decision-making, not just meet regulatory requirements.
Avoiding these pitfalls ensures that bowtie training is more than a visual activity—it becomes a practical, engaging, and meaningful tool for building safer workplaces across Canada.
Conclusion
The Bowtie method in incident investigation is more than just a diagram—it’s a mindset shift toward prevention and clarity.
By visually mapping out threats, consequences, and the barriers in between, this approach helps teams move beyond reactive thinking.
Instead of focusing solely on what went wrong, the Bowtie method promotes a balanced view of what can go wrong and what’s already in place to stop it.
In training settings, the Bowtie approach offers even more value. Its simplicity and visual format make it easy for new workers and experienced staff alike to grasp complex safety concepts.
It sparks meaningful discussion, encourages critical thinking, and helps teams see gaps in their current systems.
Unlike other methods that might feel abstract or overly technical, the Bowtie diagram brings risks and controls into plain sight.
Whether you’re in oil and gas, construction, manufacturing, or any high-risk field, using Bowtie diagrams during training builds stronger awareness and shared responsibility.
It empowers learners to not just follow safety procedures—but to understand why those procedures matter and how they fit into the bigger picture.
By making Bowtie a core part of your incident investigation training, you’re investing in a culture that thinks ahead, communicates clearly, and acts with purpose to prevent harm.