Process Standard Deviation is directly related to process variation and high process variation is not good.

A good way to view Process Sigma (or process performance) is to estimate how many process Standard Deviations would fit within the process requirements (or specifications). A higher number represents a better performing process.

Jef Spencer

Jef Spencer is a Six Sigma Consultant, Trainer and Project Coach with over 25 years of experience. He holds a Bachelor and Master Degree from Carnegie Mellon University and is ASQ and SME Certified.