Which of the following is NOT commonly used for root cause analysis?

• A. 5 Whys
• B. Ishikawa fishbone
• C. Fault Tree Analysis
• D. SWOT Analysis

Answer: (D)

Root cause analysis relies on structured methods that drill down to the underlying factors behind a problem rather than just its symptoms. The 5 Whys approach pushes you to repeatedly ask why the issue occurred until you reach a fundamental cause. The Ishikawa fishbone diagram helps organize potential causes into categories like people, process, equipment, materials, environment, and measurement, giving a clear view of how multiple factors may interact to produce the problem. Fault Tree Analysis builds a logical model showing how different prerequisites and events combine through AND/OR relationships to produce the undesired outcome, allowing precise tracing of causation paths.

SWOT Analysis, by contrast, is a strategic planning tool used to assess strengths, weaknesses, opportunities, and threats to inform decisions and strategy. It looks at the broader context and capabilities of an organization rather than diagnosing a specific incident’s root causes. While it can help frame problems or identify organizational risks, it doesn’t provide a structured mechanism to isolate the single root cause of a defect or failure.

Because it lacks the focused cause-and-effect tracing framework needed for root cause analysis, SWOT Analysis is not commonly used for RCA.