Understanding Root Cause Analysis


Root Cause is the fundamental failure or breakdown of a process which, when resolved, prevents a recurrence of the problem. A systematic approach to get to the true root causes of our process problems is Root Cause Analysis. In other words, Root Cause Analysis (RCA) is a method that is used to address a problem or non-conformance, in order to get to the “root cause” of the problem. It is used so we can correct or eliminate the cause, and prevent the problem from recurring. If we do a poor job of identifying the root causes of our problems, we will waste time and resources putting the cover on the symptoms of the problem.

 In simpler terms, Root Cause Analysis is asking why the problem occurred, and then continuing to ask why that happened until we reach the fundamental process element that failed. Generally, the RCA process involves data collection, cause charting, root cause identification and recommendation generation and implementation.

When we are talking about the analysis, we should look at the 5 Whys technique. The 5 Whys technique is an iterative process of asking “WHY” to explore the cause-and-effect relationships for a particular problem.

 We can say that asking “WHY”  5 times or in 5 steps, will give you the reason for a problem. This methodology is pretty much similar to “Cause & Effect” (Fishbone Diagram) but with the benefit of analysis that is necessary for completing the cause & effect.

1st Step –  Define the problem, articulate the problem statement, then find out whether the issue is from a caused problem or a created problem and finally determine logic to solve the problem.

2nd Step – Investigate in detail for Root Cause, then go to source of issue, be precise and do an in-depth focus and finally, go to the source of issue to get evidence and facts

3rd Step – Verify and Implement the logic, identify and evaluate the possible countermeasures, test efficient countermeasure and validate effectiveness and finally, implement and verify closure of the issue.

4th Step – Ensure the system tolerance, focus on the critical few countermeasures, identify the system root holder and additional resources for the backup and at last go to source of issue to measure results.

5th Step – After the 5th Why, the root cause is sufficiently found and ready to explore for the solution.

The purpose behind a 5-why analysis is to get the responsible and right people in the discussion for all of the possible root causes of a given defect in a process. We can have a look at the below sample problem with 5 Why technique to find the root cause. The following process of “5 Why” illustrates the steps of Root Cause Analysis to find the true root cause of a problem: Air-Conditioner not working:


  • First WHY answer– The Air-Conditioner (AC) is not working due to no electricity reaching it.
  • Second WHY answer – The Air-Conditioner (AC) is not receiving electricity because of some internal damage.
  • Third WHY answer – What’s the internal damage? The working fluid is not transferring.
  • Fourth WHY answer – The working fluid is not transferring  because the compressor and condenser are not working
  • Fifth WHY answer – The evaporator is not working (found the root cause)

We can ask for sixth, seventh or higher number of WHYs but mostly five WHYs will give you the root cause for a problem. That is why the “5 Why” is considered as a sufficient approach to analysis the root cause. Indeed the 5-Why analysis is more than just an iterative process or a simple question asking activity because of its effectiveness for solving very complex problems also.

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