After reviewing thousands of incident investigations across mining, construction, and manufacturing, a pattern emerges: the same mistakes show up again and again.
These aren't mistakes made by careless investigators. They're made by experienced safety professionals who genuinely want to prevent incidents. The mistakes are systemic, baked into how most organisations approach investigation.
Here are the five most common mistakes, and how to avoid them.
Mistake #1: Stopping at "Human Error"
The Problem
"Cause: Worker failed to follow procedure."
This is the most common, and most damaging, investigation mistake. When your cause is a variation of "the worker messed up," you haven't found a cause at all. You've found a symptom.
Human error is always the proximate cause of incidents. Someone did something (or didn't do something) that led to the event. But that tells us nothing useful.
The question isn't what they did wrong. The question is why was it possible for them to do it wrong?
Why This Happens
- It's the easiest conclusion, you can see the error clearly
- It feels satisfying, someone to "blame"
- It's fast, investigation can close quickly
- It protects the organisation from harder questions
The Fix
When you identify a human error, ask "why was this error possible?" at least five more times. The worker didn't follow the procedure, why? Was it practical? Were they trained? Was there pressure to shortcut? Was the hazard even visible?
Mistake #2: Writing Weak Corrective Actions
The Problem
"Corrective action: Retrain all workers on the procedure."
If retraining solved problems, we'd have zero incidents by now. Workers are trained constantly. And yet incidents keep happening.
Retraining, adding warning signs, and "reminding workers to be careful" are all administrative controls, the weakest level on the hierarchy of controls. They rely on perfect human behaviour, every time, forever.
That's not how humans work.
The Hierarchy of Controls (Most → Least Effective)
- Elimination: Remove the hazard entirely
- Substitution: Replace with something less hazardous
- Engineering controls: Physically prevent exposure
- Administrative controls: Change how people work
- PPE: Protect the individual
Most corrective actions cluster at levels 4 and 5. That's why incidents recur.
The Fix
For every corrective action, ask: "Is there something higher on the hierarchy we could do instead?" If your action requires humans to remember something or choose correctly every time, it will eventually fail.
Mistake #3: Confirmation Bias
The Problem
You arrive at the scene with a theory. You gather evidence that supports your theory. You conclude your theory was correct.
It's human nature. We form hypotheses quickly (often within minutes of hearing about an incident) and then seek evidence that confirms them. Evidence that contradicts our hypothesis? We minimize it, explain it away, or don't notice it at all.
The result: investigations that feel thorough but miss critical contributing factors.
Signs of Confirmation Bias
- You knew the "cause" within the first hour
- All the evidence points the same direction (too neatly)
- Witnesses who disagreed with your theory were "mistaken"
- The conclusion matches what management expected
The Fix
Deliberately seek disconfirming evidence. Ask: "What would have to be true for my current theory to be wrong?" Interview witnesses before forming conclusions. Have someone outside the investigation review your findings with fresh eyes.
Mistake #4: Not Reaching Organisational Factors
The Problem
Investigation identifies equipment failure and procedural gaps, but never asks: "What management decisions created these conditions?"
Equipment doesn't maintain itself. Procedures don't write themselves. Training doesn't happen automatically. Behind every immediate cause is an organisational factor, a decision, system, or cultural element that allowed the conditions to exist.
These are the true underlying causes. And most investigations never reach them.
Why Investigations Stop Short
- Organisational factors are uncomfortable, they implicate management
- They're harder to identify than physical causes
- They require deeper analysis and more time
- There's often organisational pressure to keep it simple
The Fix
Use the ICAM organisational factors framework. For every equipment, procedural, or human factor you identify, ask: "What organisational decision or system allowed this?" Budget? Training? Supervision? Management priorities? Change management?
Mistake #5: Investigating in Isolation
The Problem
Each incident is investigated as if it's unique. No one connects the dots across multiple events.
Organisations experience patterns of incidents, similar contributing factors appearing again and again. But because each investigation is siloed, the pattern remains invisible.
How many times has your organisation had incidents where:
- Shift handover communication was a factor?
- Time pressure contributed?
- Contractor management was involved?
- The procedure was outdated or impractical?
If you can't answer that immediately, you're investigating in isolation.
The Fix
Implement trend analysis across investigations. Tag contributing factors consistently. Review patterns quarterly. When the same organisational factor appears in multiple incidents, address it at the systemic level, not one incident at a time.
The Meta-Mistake: Treating Investigation as Compliance
Underlying all five mistakes is a deeper issue: many organisations treat incident investigation as a compliance exercise rather than a learning opportunity.
When the goal is to complete the form, close the case, and satisfy the regulator, investigations become superficial. When the goal is to genuinely understand what happened and prevent recurrence, investigations become powerful.
"The quality of your investigations reveals whether your organisation truly wants to learn, or just wants to look like it's learning."
How to Fix Your Investigation Process
- Adopt ICAM methodology: It's specifically designed to reach organisational factors.
- Train investigators properly: Investigation is a skill, not just common sense.
- Allow adequate time: Rushing guarantees shallow results.
- Create psychological safety: Investigators need freedom to report uncomfortable findings.
- Track and trend: Connect the dots across multiple incidents.
- Measure corrective action effectiveness: Did it actually work?
Stop Making These Mistakes
InvestigatePro guides investigators through proper ICAM methodology, prompts for organisational factors, and automatically tracks trends across incidents. No more superficial investigations.
Building a Better Investigation Culture
Lasting improvement requires more than fixing individual investigation reports. It requires building an environment where honest incident reporting is rewarded, investigators have the time and training to go deep, organisational factors can be named without political consequences, and corrective actions are tracked until they demonstrably reduce risk. That's a culture question as much as a methodology question, and it starts with how senior leaders respond when an investigation implicates management systems rather than worker behaviour. When leaders protect the process, the process improves. When they protect their own decisions, investigations stay shallow. Investing in structured methodology, and the training, time, and psychological safety that make it effective, is one of the highest-leverage actions a safety leader can take.
Conclusion
If the same types of incidents keep happening in your organisation, the investigation process itself is the problem. The five mistakes above, stopping at human error, weak corrective actions, confirmation bias, not reaching organisational factors, and investigating in isolation, are systemic issues that require systemic solutions.
The good news: they're all fixable. It starts with recognizing that investigation isn't about finding someone to blame. It's about finding something to fix.