Which term is commonly associated with reducing variation in processes, used in SPC?

• A. Kaizen
• B. DMAIC
• C. 6 Sigma
• D. Pareto

Answer: (C)

Reducing variation in processes is a central aim of quality control, and Six Sigma is the term most closely associated with that goal. It uses data-driven methods to identify and remove the causes of variation so processes produce consistent, predictable results. In Statistical Process Control, variation is monitored with control charts, and Six Sigma projects use Define-Measure-Analyze-Improve-Control to systematically remove sources of variability and push process capability toward the six-sigma level (about 3.4 defects per million opportunities). While Kaizen emphasizes ongoing small improvements, Pareto analysis helps prioritize the most impactful problems, and DMAIC is the improvement cycle used within Six Sigma, the term that best captures the aim to minimize variation is Six Sigma.