where did the name six sigma come from
Six Sigma The term Six Sigma (capitalized because it was written that way when registered as a Motorola trademark on December 28, 1993) originated from terminology associated with statistical modeling of manufacturing processes. The maturity of a manufacturing process can be described by a sigma rating indicating its yield or the percentage of defect-free products it creates. A six sigma process is one in which 99.99966% of all opportunities to produce some feature of a part are statistically expected to be free of defects (3.4 defective features per million opportunities). Motorola set a goal of "six sigma" for all of its manufacturing operations, and this goal became a by-word for the management and engineering practices used to achieve it.
At sixes and sevens An ancient dispute between the Merchant Taylors and Skinners livery companies is the probable origin of the phrase.[1] The two trade associations, both founded in the same year (1327[2]), argued over sixth place in the order of precedence. In 1484, after more than a century and a half of bickering, the Lord Mayor of London Sir Robert Billesden ruled that at the feast of Corpus Christi, the companies would swap between sixth and seventh place and feast in each other's halls. Nowadays, they alternate in precedence on an annual basis.[1][2]