Special Cause Variation refers to variation in a process which is sporadic and non-random. All processes contain Common Cause Variation, but processes that exhibit Special Cause Variation do not perform in a predictable manner and are technically not in Control.

Once Special Cause Variation has been identified it should be addressed specifically and fixed or planned for. Unlike Common Cause Variation, this is generally possible without significant modifications to a system.

For a better understanding of Special Causes and an overview of Lean Six Sigma, check out our Free Lean Six Sigma Yellow Belt Training, Green Belt Training or Lean Training.

Elisabeth Swan

Elisabeth is a Managing Partner & Executive Advisor at GoLeanSixSigma.com. For over 25 years, she's helped leading organizations like Amazon, Charles Schwab and Starwood Hotels & Resorts build problem-solving muscles with Lean Six Sigma to achieve their goals.