Greek and Roman lettering used in formulas is derived from the scientist or theorist that developed the formula. Sigma represents stress directly. When a formula uses a capital or lwercase f, it is referring to stress as a type of force., hence the letter choice.
The motto of Phi Sigma Phi is 'Do unto others as you would'.
The motto of Sigma Lambda Alpha is 'Latinas Helping Others'.
The sigma sign (Σ, which resembles a sideways M) represents the sum of. Sometimes there are numbers above and below the sigma sign. For example, below the sigma sign can be written x=2, and above the sigma sign can be written 6. This signifies the sum of the numbers between the number below, and the number above. If there is a formula alongside this, it signifies that you should apply the formula to each number, and add the numbers together (hence the Σ, sum of, sign).
Barbara Wheat has written: 'Seis Sigma'
Small sigma (σ) typically represents the standard deviation in statistics, which measures the amount of variation or dispersion in a set of values. A small sigma indicates that the values are closely clustered around the mean, while a larger sigma suggests more spread out data. In the context of physics or engineering, small sigma can also denote stress in materials.
Chandler Harris has written: 'Fraternity manual of Delta Sigma Phi Fraternity' -- subject(s): Delta Sigma Pi, Handbooks, manuals
Paul A. Keller has written: 'Six Sigma Deployment'
Different symbols are used but if you are referring to the greek symbol "σ", it is pronounced "sigma" (like stigma without the t).
Douglas Richard Carlson has written: 'The history of the Sigma Chi Fraternity, 1955-1980' -- subject(s): History, Sigma Chi Fraternity
Jay Arthur has written: 'Guia Para El Instructor De Six Sigma' 'Six Sigma Simplified' 'Six Sigma Simplificado' 'How to motivate everyone' -- subject(s): Achievement motivation, Motivation (Psychology) 'Debug Your Mental Software'
Catherine Patton has written: 'Six sigma in a transactional environment'
There is no company called Six Sigma Program, instead Six Sigma is a set of tools used by business and others that improves process outputs by identifying and removing error and reducing variability in manufacturing and business processes.