How to Use Six Sigma to Improve Documentation 
Six Sigma is a tool you can use to ensure that your documentation is satisfying customer needs and expectations. The three case studies provided demonstrate ways in which Six Sigma has helped us make our documentation more effective by finding out more about the customer and getting the customer more involved. This paper does not teach Six Sigma methodology or its statistical background.
Beard, Lori and Erin Beal Welch. STC Proceedings (2002). Articles>Documentation>Methods