Root cause analysis is a core step in all problem-solving methodologies, including 8D, Six Sigma, A3, and even PDCA. The reason is simple: rather than focusing on the surface-level issue, we go straight to the origin of the problem. If we eliminate this root cause, the issue will be permanently resolved.
We use various techniques to find root causes, such as Fishbone Diagrams, Fault Tree Analysis, and 5 Whys. Among these, the 5 Whys method is the most common in manufacturing industries.
We keep asking “why?” repeatedly, ideally five times, to drill down to the root cause.
But what about technical and systemic root causes? Do we need different types of analysis to find them? And once we identify the root cause, how do we decide whether an action is corrective or preventive? Is it as simple as saying, “This prevents the issue, so it’s preventive”?
The simple answer is no. Let’s take a closer look.
Technical Root Cause & Corrective Action
The technical root cause is the technical origin of the issue, the one we typically identify in all problem-solving studies. Let’s take a simple example. The problem is “Punctured Tire” If we apply 5 Whys method, we can identify the technical root cause following:
- Why did the tire puncture? → The tire had low air pressure.
- Why was the tire pressure low? → The tire was not regularly checked for air pressure.
- Why was the tire not regularly checked? → The vehicle owner did not follow a maintenance schedule.
- Why did the vehicle owner not follow a maintenance schedule? → Lack of awareness about the importance of regular tire checks.
- Why was there a lack of awareness? → The vehicle owner was not properly educated on vehicle maintenance.
So, our technical root cause is vehicle owner was not properly educated about vehicle maintenance. If we take an action against this root cause like: Provide better education for vehicle owners about tire maintenance. That would be the corrective action, as it addresses the technical root cause that we’ve identified here.
We fixed the technical root cause, so you can think that we sorted out the issue….. technically, yes. But we didn’t eliminate the reason behind it. What is the underlying reason behind this last cause? In other words, the root cause can repeat, because we have not prevented the root cause, we just corrected it.
Systemic Root Cause & Preventive Action
The way is simple, we’ll just ask one more “Why”. This last question will take us where we see the lack of standard. Let’s go one step further and ask one last ‘Why?’ — this is where we find the systemic root cause
Why wasn’t the vehicle owner properly educated on vehicle maintenance ?
The systemic root cause here is that “There is no standardized system in place to educate vehicle owners about routine maintenance, including tire pressure checks.” So, based on that, our preventive action would be “to implement mandatory maintenance reminders through automakers and service centers to ensure regular tire pressure checks.” This action prevents the re-occurring of technical root cause, because simply we standardized that.
Key Takeaways
We started with a simple punctured tire problem, but it led us to analyze a much broader issue. In this article, the key point is this:
- Fixing the problem itself is a containment action.
- Fixing the technical root cause is a corrective action.
- Fixing the systemic root cause is a preventive action.
If you want to learn more about Root Cause Analysis and CAPA, you can check out my Udemy course
Mete Kilic 
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