The inherent process reflected by measures of process performance, sometimes referred to as “voice of the process.” Techniques such as control charts, confidence intervals, and prediction intervals are used to determine whether the variation is due to common causes (i.e., the process is predictable or “stable”) or is due to some special cause that can and should be identified and removed.

1. This glossary is from Appendix C of Technical Report CMU/SEI-2002-TR-004.
2. ® CMMI is registered in the U.S. Patent and Trademark Office by Carnegie Mellon University.