4

Ø The Greek symbol “Sigma” which means standard deviation; a measure of variation

Ø As Sigma (s, s) gets smaller the error in predicting the result gets smaller

s = Standard Deviation

Ø A statistical measure of a process’s ability to meet customer requirements (CTQs)

Ø Process Six Sigma equates to 3.4 defects per million opportunities or a Cpk =2

s = Measure of Process

Capability

Standard Deviation and Process Capability

Yield DPMO Sigma

69.2% 308,000 2

93.3% 66,800 3

99.4% 6,210 4

99.977% 230 5

99.99966% 3.4 6

Yield DPMO Sigma

Cpk = ~1.33

Cpk = 2

Six Sigma Methodologies Overview

-6s -3s -2s -1s x +1s +2s +3s +6s

Sigma Percent

+/-1 sigma 68.27

+/-2 sigma 95.45

+/-3 sigma 99.73