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Root Cause Analysis (RCA) Basics
Full Brim Safety: Build Smart, Build Safe
The Safety Man
October 30, 2025
Root Cause Analysis (RCA) Basics
Welcome back, let's Build Smart & Build Safe! We’ve covered securing the scene and collecting evidence. Today, we focus on the most important investigative step: Root Cause Analysis (RCA) Basics.
RCA is the structured process of drilling down past the obvious, surface-level causes of an accident to find the deep, systemic flaws that allowed the incident to happen. The goal is to prevent recurrence by fixing the original problem.
Moving Beyond the Direct Cause
When an incident occurs, we quickly identify the Direct Cause (e.g., "The scaffold platform broke," or "The worker slipped"). However, stopping the investigation there only addresses the symptom, not the disease.
RCA requires investigators to ask "Why?" repeatedly until they identify a point where an organizational or management system failure allowed the direct cause to occur. This is the Root Cause.
Level of Cause | Example Question | Example Answer |
Direct Cause | What was the final, immediate trigger? | The worker fell from the ladder. |
Contributing Cause | Why did the fall happen? | The ladder was not tied off and slid sideways. |
Root Cause | Why was the ladder not tied off? | The new worker was never trained on the 4:1 rule and tie-off procedures. (The system failed to train the worker.) |
The "Five Whys" Technique
A simple and effective tool for basic RCA is the Five Whys. By asking "Why?" five times (or more, or less, until you reach a non-blaming systemic issue), you peel back the layers of the problem:
Why did the grinder catch fire? Because the motor was too hot.
Why was the motor too hot? Because the daily inspection checklist was skipped.
Why was the checklist skipped? Because the supervisor didn't enforce the pre-use inspection policy.
Why didn't the supervisor enforce the policy? Because they were overburdened and focused only on production numbers.
Why is the supervisor only focused on production? Because the company's reward and accountability system doesn't prioritize safety compliance. (Root Cause: Organizational Priority/Policy Failure).
Once the Root Cause is identified, the corrective action is clear: You don't just replace the grinder; you fix the company's internal priorities and accountability system.
Tomorrow, on Fall Protection Friday, we'll connect investigation techniques to near-miss reporting and post-fall equipment quarantine.
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-The Safety Man
