Main Page | See live article | Alphabetical index In Continuous Process Improvement (CPI), a root cause is the most basic reason for a defect or problem in a product or process. Elimination of the root cause leads to the elimination of the defect or problem. Tools such as the 5 Whys ot the Fishbone or Ishikawa diagram are used to identify the root cause of a problem or defect as part of a CPI project aimed at improving product or process quality. External link Root Cause at Six Sigma This article is a stub. You can help Wikipedia by fixing it. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.