Six Sigma

Data- and method-driven improvement philosophy — target: process capability at level (≈ 3.4 defects per million opportunities).

Also known as: Six Sigma, 6-sigma

Six Sigma is a management approach for systematic process and product improvement grounded in statistical methods. The eponymous figure corresponds to a process capability of Cpk ≈ 2.0 and a defect rate of about 3.4 ppm assuming the customary 1.5σ long-term shift.

  • Origin — Motorola, mid-1980s (Bill Smith); GE (Jack Welch) took it worldwide
  • FrameworkDMAIC (improving existing processes), DMADV (new development)
  • Roles — Yellow / Green / Black / Master Black Belts, Champions, Sponsors
  • Toolkit — statistical (tests, regression, DoE, SPC) and qualitative (SIPOC, Ishikawa, 5-Why, Pareto)

See also

Used in

Sources

  • Pyzdek, T. & Keller, P. — The Six Sigma Handbook, 5th Edition, McGraw-Hill
  • Harry, M. & Schroeder, R. — Six Sigma: The Breakthrough Management Strategy, Currency/Doubleday, 2000
  • Montgomery, D. C. — Introduction to Statistical Quality Control, 8th Edition, Wiley