Sigma [σ]

Sigma (σ) is the Greek letter S and in statistics, it is used as the symbol for the standard deviation of a population. It answers the question “How much does my process vary?”.

Causal Thinking: y=f(x)

Six Sigma builds on causal thinking to solve problems sustainably. It is important to stop fire-fighting and work to eliminate the root causes of problems. The equation y=f(x) stands for cause and effect: Whenever there is something you want to change (Y), you should...