Within various aspects of a quality management system, there is a directive to evaluate the root cause of an issue – this could be risk management, investigations, non-conforming material, corrective actions, etc. There is a specific process to this concept, along with methods to achieve the answers.
A root cause is a factor, or combination of factors, that caused a non-conformance. Root Cause Analysis is a term that describes the approaches, tools and techniques used to identify what caused the initial problem. Identification of this issue should lead to the eventual elimination through process improvement. By understanding why an event happened, you will be able to further develop effective recommendations for improvement.
Root Cause Analysis can help identify the what, how and why behind the event, therefore helping to prevent recurrence. The issue is reasonably identifiable, can be controlled by management (Mother Nature is an example of something management cannot control), and will allow for generation of recommendations for improvement. In most investigations, it is easy to identify “operator error” as the cause. While this may be an accurate description of what and how the event was caused, it does not tell you why the mistake occurred. Therefore, you are unable to identify ways to prevent it from happening again.
There is a four-step process for Root Cause Analysis:
- Step 1 – Data collection
- Step 2 – Casual Factor charting (a method to organize and analyze information gathered)
- Step 3 – Root cause identification
- Step 4 – Generation of recommendations, implementation
There are numerous methods to use in Root Cause Analysis, including: The 5-Whys Analysis, Barrier Analysis, Change Analysis, Fault Tree Analysis (FTA), Failure Mode and Effects Analysis (FMEA), Fish-Bone Diagram, and Pareto Analysis.