What is 6 Sigma? What is the Six Sigma Definition?

Six Sigma definition

– A process quality measure indicating that there are 6 standard deviations between the process average and EACH (lower & upper) specification limit.  Therefore, the greater the number of s’s, smaller the variation (the tighter the distribution) around the average, it will produce approximately 3.4 Defects Per Million Opportunities.

6 Sigma Definition Explained:

In the recent years, Six Sigma certification has become more and more popular in the business world. Due to its relatively new implementation, though, many people aren’t familiar with exactly what it is and how it can positively affect business models. By gaining a better understanding on the world of Six Sigma, you can quickly learn its enormous benefit to your bottom line and stronger business practices.

The concepts behind Six Sigma are, basically, those of statistical probability. In layman’s terms, this basically means how confident you are that what you need to happen will happen. By using Six Sigma principles, the idea is to close the gap between what does happen and what should happen as well as increase your confidence on these two issues.

At the very bottom of it all is the fact that everything we do, even if it is ever so slightly, varies from what we intend to do. Since most things can be absolutely exacting, we think in terms of a range of acceptability, better known as a tolerance range. These tolerance ranges are designed with the customer in mind and respond to the needs and expectations of our customers.

If you are manufacturing something such as widgets that need to be cut to 1”, you develop a tolerance limit. If it’s something minor like a napkin holder something like 1’1/16” may be perfectly acceptable. If it’s a screw for the space station, this would be off the charts for unacceptability. But every widget you create will vary ever so slightly from the next and so on.

This data can all be compared on something called a distribution curve.
These distribution curves tell us not only what our process has done but what it is likely to do next. Before Six Sigma certification, the belief was that high levels of quality cost more than low levels of quality, effectively raising price and making you less competitive. Balancing quality with cost became the magical formula for success.

But now knowing what we know through Six Sigma, we have learned that high quality doesn’t cost more money to produce. In all actuality, it costs less. The cost of quality is actually the cost of quality deviation in terms of things like reworking products, scrap materials, and warranty claims. By implementing a Six Sigma plan, you can effectively reduce this deviation, raising your product quality, eliminating added expenses, and creating a happier customer who now has a better product. That, in a nutshell, is the six sigma program.

Read more about the history of Six Sigma and the Lean Six Sigma definition.
If you’d like to learn more about the different levels of training from the yellow to the black belt process, click here.