Every incident is an opportunity to stop the next one.
Most investigators have used the 5 Whys at some point. It is quick, simple, and can be sketched out in a few minutes. But when you work in high-risk industries, you have to do your best to dig past the first explanation and uncover what really set the conditions for failure.
Incidents never have just one root cause, and surface-level answers can leave dangerous gaps in understanding.
What is the 5 Why’s methodology?
The 5 Whys is a step-by-step method of asking “why” until you reach a point where you feel you have got to the root of the problem.
Problem: Machine A stopped unexpectedly.
Why 1: Why did it stop? Because a fuse blew due to circuit overload.
Why 2: Why was there an overload? A bearing wasn’t lubricated, causing it to seize and overload the circuit.
Why 3: Why was the bearing under-lubricated? The oil pump wasn’t circulating enough oil.
Why 4: Why was the pump delivering insufficient oil? Its intake was clogged with metal shavings.
Why 5: Why was the intake clogged? There was no filter to prevent debris.
The 5 Whys has earned its place as a common entry point for root cause analysis. It’s quick, easy to understand, and requires little formal training. But when there are multiple contributing factors including human decisions, organisational pressures, and environmental conditions, the 5 Whys can stop short.
The limitations of 5 the Whys vs the COMET methodology for RCA
Depth of insight
5 Whys: By design, the 5 Whys follows a single chain of questioning. It risks oversimplifying complex incidents and can stop at a convenient explanation. Two investigators might land on two completely different “root causes,” each believing they are right.
COMET: COMET prompts teams to look across multiple domains (Communication, Operating Environment, Management, Equipment, and Training). This guarantees a deeper, broader analysis that captures systemic, organisational, and human factors, leading to a much deeper understanding of incidents.
Consistency and repeatability
5 Whys: Outcomes can vary widely depending on who is leading the analysis. With no standardised approach, results can be inconsistent, subjective, and difficult to compare across teams or sites.
COMET: COMET provides a consistent framework with structured workflows and outputs. Every investigation follows the same methodology, producing comparable results across teams and locations. This is how you build organisational learning instead of scattered one-off reports.
From reactive to proactive
5 Whys: Each investigation conducted using 5 whys lives in isolation and findings rarely connect to wider organisational trends, often leading to repeat failures.
COMET: COMET centralises investigation data and makes it accessible across those teams who need visibility. Through reporting and dashboards COMET allows you to spot patterns and trends to be acted upon, transforming incident investigations into proactive learning opportunities that prevent recurrence.
Data-driven decisions
5 Whys: Usually conducted on paper or whiteboards, 5 whys produces narrative results that are hard to aggregate, analyse, or integrate into wider systems. This makes it difficult to use the findings for strategic decision-making.
COMET: COMET is digital-first and integrates with leading EHS platforms. Data from investigations is stored in structured formats, making it searchable, measurable, and linkable to wider performance metrics.
Confirmation Bias
5 Whys: Can encourage teams to follow the first line of thought that feels right and stop there. Investigators may unconsciously look for evidence that supports their assumption instead of challenging it.
COMET: Prompts investigators to consider multiple potential causes and weigh evidence systematically. This reduces the risk of confirmation bias and ensures findings reflect the true drivers of failure, not just what seemed likely at first glance.
Human Factors analysis
5 Whys: The 5 whys methodology can often end with “human error” as a root cause, without exploring the organisational or environmental factors behind it, leading to blame rather than learning.
COMET: COMET integrates accredited Human Factors Analysis functionality, allowing investigators to assess the role of human factors in incidents. By considering human factors alongside technical and organisational aspects, COMET ensures a holistic understanding of incident causation, leading to more effective preventive measures.
Industry-ready assurance
5 Whys: Informal, lightweight outputs may not satisfy regulators, auditors, or clients in high-risk industries. The lack of rigour makes it difficult to demonstrate accountability or due diligence.
COMET: COMET produces auditable, structured reports trusted by regulators and industry leaders. Findings are detailed, transparent, and backed by clear evidence. This builds confidence with clients and external stakeholders, demonstrating robust safety and compliance practices.
Why COMET is the new standard in root cause learning
Like other single-case RCA methods, the 5 Whys will keep getting used by organisations that are not ready to move from managing incidents to truly preventing them. It feels quick and it gives an answer, but an answer is not the same as right one. In complex, high-risk events, stopping at the first “root cause” leaves risk sitting there, waiting for the next incident.
COMET for investigations & RCA was built for organisations that want to raise the standard. When lives, assets, and reputations are at risk, you need depth, structure, and evidence you can trust. COMET delivers exactly that, a consistent, rigorous process that uncovers systemic drivers and turns findings into actionable improvements.
Not every event needs a comprehensive investigation. However, high-volume, lower-potential incidents still need to be investigated properly or they become blind spots. That is why we created COMET Lite, the practical alternative to 5 Whys. It keeps the rigour, but does it in around 60 minutes so nothing slips through the cracks.
With COMET Lite you can:
Discover and analyse: Capture the circumstances of the event, select relevant root causes from COMET’s Root Maps, and complete barrier and change evaluations.
Review and act: Assign at least one preventive action per root cause, use built-in prompts to guide better actions, and review supporting evidence before closure.
Summarise and close: Finalise incident data, prepare a clear executive summary, and log latent issues for trending and organisational learning.
This means even smaller events feed into your overall safety picture instead of disappearing into someone’s notebook. No more backlog, no more missed learning.
Two solutions, one license
Every COMET license includes both COMET for investigations & RCA and COMET Lite, so you can match the depth of the investigation to the severity of the incident:
COMET for investigations & RCA:
• SIF (Serious Injury or Fatality)
• PSIF (Potential Serious Injury or Fatality)
• Recordable Incident
• First Aid Incident
COMET Lite for near misses and other low-severity events where speed and consistency matter.
This gives you one system that handles everything from the most serious event to the smallest near miss. You can see trends across all incident types, close the loop on preventive actions, and move your organisation away from repeat failures.
Learn more about COMET for RCA and Investigations, and COMET Lite here.
Is COMET the right tool for your organisation?
If you want to move the dial from reacting to prevention, COMET gives you the tools to do it. It brings structure, data, and consistency so you can see the whole picture and build lasting resilience.
Want to learn more?
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