A clear definition of Six Sigma is that it is
a process-focused methodology designed to improve business performance through improving specific areas of a strategic business processes.
The term Sigma symbolizes how much deviation exists in a set of data – sometimes called a bell curve, or a standard normal distribution. In a standard normal distribution, 50% of the values lie above the mean (average) and 50% of the values lie below.
For example, your business is manufacturing carton boxes and you set a production target of 1 million carton boxes. If you reject 66,807 carton boxes then you’re running at 3 Sigma. If you reject an average if 3.4 carton boxes, then you are at 6 Sigma.
That is fundamentally how Six Sigma measures quality. It measures the Variance and does not rely on the Mean. The popular notion is that all too often businesses base their performance on a mean, or average-based measure, of the recent past. However, in reality customers DON’T judge businesses on averages. They actually experience the variance in each and every transaction or purchase. Moreoever, they also put value on products and services that deliver high levels of quality.
Six Sigma focuses first on reducing variation, and then on improving process capability. It is therefore a statistical unit of measurement reflective of two things: (1) process capability and (2) process performance, i.e., variation. In other words, the higher the Sigma value, the lesser the chance of a defect.
Below are the Levels of Six Sigma.
Six Sigma level ? produces less than 3.4 defects in a million opportunities.
Five Sigma level ? 233 defects in a million opportunities.
Four Sigma level ? 6,210 defects in a million opportunities.
Three Sigma level ? 66,807 defects in a million opportunities.
Two Sigma level ? 308,537 defects in a million opportunities.
One Sigma level ? 697,672 defects in a million opportunities.
Interesting? Click on the URL below for a Six Sigma Management Kit.
