Why do Black Belts and Master Black Belts conduct closed-looped assessments of Six Sigma implementation?

[answerhappygod]

Why do Black Belts and Master Black Belts conduct closed-looped assessments of Six Sigma implementation?

To ensure all aspects of Six Sigma have been implemented
To assure privacy of the people involved in Six Sigma projects
To ensure competitors do not get the information on the improvements achieved
To minimize influencing people with the Six Sigma project measurements and avoid any manipulation