Special Cause

3 Definitions

The cause(s) of variation in a process which have a source that is identified, and can be eventually eliminated. [Same as assignable cause] / Or / Causes of variation in a process that are not inherent in the process itself but originate from circumstances that are out of the ordinary. Special causes are indicated by points that fall outside the limits of a control chart
defined by 6SixSigSigma
A source of variation that is intermittent, unpredictable, unstable; sometimes called an assignable cause. See assignable cause.
defined by Lean Affiliates
Special cause variation causes a process to go out of control, as typically observed on a control chart. Not present when the process in in-control. Special causes have specific root causes which can be found and corrected (in contrast with common cause variation which is the effect of all the small unknown things that change each time a process is run).