Six Sigma for Managers, Second Edition (Briefcase Books Series), 2nd Edition

Improve Phase

To improve is to change; to be perfect is to have changed often.

—Winston Churchill (1874-1965)

This phase is usually initiated by selecting those product or process performance characteristics that must be improved to achieve the goal. Those characteristics are then diagnosed to reveal the major sources of variation. Next, the key process input variables (Xs) are identified through statistically designed experiments. Proven process variables that have been filtered through the Analyze phase and are identified as the vital few Xs are included in the experiment. The goal now is to form the Y = f(X) relationship to be leveraged and ...