What is Six Sigma?
Six Sigma is a quality and business improvement philosophy which was
originally developed by Motorola during the eighties. The term Six Sigma (also
written 6σ) has its origin in mathematics
where Sigma means standard deviation (a measure for
spread in a set of data).
On long term, a Six Sigma process has no more
than 3,4 defect units per one million produced. 
Follow this link to learn more about Six Sigma DMAIC
