Which root cause analysis methods are commonly used in the CAPA process?

• A. 5 Whys and Ishikawa diagrams.
• B. SWOT and PESTLE.
• C. Cost-benefit analysis.
• D. Random sampling.

Answer: (A)

In CAPA, finding the underlying cause of a problem is essential, not just describing what happened. The most effective and commonly used root-cause techniques are 5 Whys and Ishikawa diagrams.

The 5 Whys approach is a simple, iterative questioning method. Start with the problem and ask why it occurred; then take the answer and ask why again, continuing this chain until you reach a fundamental cause. This helps teams drill down beyond symptoms to actionable issues that, once addressed, prevent recurrence.

Ishikawa diagrams, or fishbone diagrams, provide a visual way to explore possible causes across categories such as people, machines, methods, materials, measurements, and environment. By mapping potential factors to the problem, it becomes easier to see which areas need deeper investigation and which root causes are most plausible.

Together, these tools support effective corrective actions to eliminate root causes and preventive actions to avert similar issues in the future.

SWOT and PESTLE are strategic planning tools, not methods for diagnosing a specific nonconformity. Cost-benefit analysis weighs the economics of actions rather than identifying why a problem occurred. Random sampling is a data-collection technique that can support analysis but does not by itself reveal root causes.