Six Sigma(6&sigma) is a disciplined, data-driven approach to process improvement aimed at the near-elimination of defects from every product, process, and transaction. The purpose of 6&sigma is to gain breakthrough knowledge on how to improve processes to do things BETTER, FASTER, and at LOWER COST. It can be used to improve every facet of business, from production, to human resources, to order entry, to technical support. 6&sigma can be used for any activity that is concerned with cost, timeliness, and quality of results. Unlike previous quality improvement efforts, 6&sigma is designed to provide tangible business results, cost savings that are directly traceable to the bottom line.
6&sigma is a rigorous approach designed to improve the quality and efficiency of any business process. In fact the goal is to provide a statistical minimum in the number of defects allowed in any functional entity of a business. Data is collected, analyzed using the tools of 6&sigma and perfected with the knowledge gained. When the methodology is performed correctly a statistically perfect system is the result.
The name 6&sigma is taken from the concept of a normal or bell curve. When you take the standard deviation of a bell curve, it is often designated with the Greek letter &sigma. The following table shows what the probability of being outside of 1-6 sigmas on a bell curve.
| Sigma | Defects/Million | Probability |
| 1 | 700,000 | 70% |
| 2 | 330,000 | 33% |
| 3 | 70,000 | 7% |
| 4 | 8000 | .8% |
| 5 | 300 | .03% |
| 6 | 3 | 0.0003% |
As you can see 6 sigma stands for the goal of 3 defects per million. That gives a probability of a defect being 0.00003%. Most people would be happy with 5 standard deviations giving a probability of .03% for a defect. It is apparent that 6 sigma is a very high standard to aim for.
Overview Of Six SigmaGet the 30,000 foot view of 6&sigma.
What Is 6&sigma?This article's purpose is to define six sigma. You will learn what it is and how it is used.
Steps in 6&sigma MethodologyThe methods used to acheive the 6 sigma goal of 3 defects per million.
6&sigma ToolsA summary of some of the tools used in 6 sigma analysis.
6&sigma CoursesInformation about training for the various belts or levels of 6 sigma expertise.
