Glossary · S
Six Sigma
A structured approach to reducing variation and defects
What it means
Six Sigma uses data and statistical methods to improve process performance and reduce defects. DMAIC stands for Define, Measure, Analyse, Improve and Control. The commonly cited 3.4 defects per million opportunities relies on a specific statistical convention and is not a guaranteed project outcome.
What it means for a business
A team can define a recurring quality problem, measure its frequency, investigate causes, test improvements and monitor the result. The business value depends on the problem, data and sustained process changes rather than a standard return-on-investment percentage.