Overview

We established earlier that Six Sigma is a set of business concepts and methodologies designed to address your Customer's Critical Criteria, the demands for high quality, and defect-free product and service processes. Customer satisfaction and continuous improvements are critical factors in the success equation of any business.

This chapter explores the implementation of Six Sigma deployment. We feel that no company can become successful in implementing Six Sigma methodologies without integrating the supply base. Six Sigma has several different meanings, depending upon the context in which it is used. We have discovered that many people attempting to learn about Six Sigma become confused as a result of these many uses of the term and its definition.

Sigma is the eighteenth Greek letter. Capitalized it is ?, and in lower case ?. The upper case is frequently used as a summation of numbers.

For example:

The lowercase ? is used in statistics to denote the standard deviation of the population.

The standard deviation ? is the square root of the variances ? ². The variance for a population is given by:

Stated in words:

• Take the difference between each individual value and the mean.

• Square that difference.

• Sum all the squared differences.

• Divide the sum by the total number in the population.

Most of the time we are working with a sample, and the variance (s ²) for the sample is:

Note that the sample variance is calculated using the number of samples minus...