Which analytical technique is used to determine the basic underlying reason for a variance or defect?

• A. Root Cause Analysis
• B. Risk Assessment
• C. Quality Improvement
• D. Data Mining

Answer: (A)

Root cause analysis identifies the fundamental reason a variance or defect occurs, rather than just addressing symptoms. By tracing the issue through data and processes, it uses tools like 5 Whys or Ishikawa diagrams to uncover the underlying system, workflow, or human factors that set the stage for the problem. Once the true cause is identified, targeted corrective actions can prevent recurrence rather than merely treating the result. Risk assessment looks at likelihood and impact of potential problems, not diagnosing why one occurred. Quality improvement is broader and aims to enhance processes, but may not pinpoint causal factors without focusing on underlying causes. Data mining surfaces patterns in data but doesn’t inherently establish cause-and-effect. So root cause analysis is the approach best suited for determining the basic underlying reason for a variance or defect.