Errors are six standard deviations out
Another page on this site is named "Overview of Six Sigma". This "What is Six Sigma" page goes a little deeper to give a finer definition of Six Sigma.
Six Sigma is built upon data. It is a data-driven analysis of your company in key areas. The focus is on the supply chain. How do you know what changes to make? The data shows you where the waste is and what changes are needed.
This is a 30-second summary of what is Six Sigma
With Six Sigma, you
Six Sigma was implemented by the Motorola corporation in 1986 as a spin-off of Total Quality Management (TQM). An engineer there named Bill Smith developed the technique. He named it after the fact that it was the latest outgrowth of six decades of quality improvement techniques created and used by the company including TQM, "Zero Defects", and strong quality control management.
It took Bill Smith a long time to finally convince the heads at Motorola that Six Sigma could work.
Originally, Six Sigma was implemented to create products without defects. Defects in products are seen as the most wasteful thing in Six Sigma (although waste can be found in other places, too). Smith said that an average of no more than 3.4 defects for every one million products was realistic.
Six Sigma started in just the manufacturing sector. It has evolved so it can be used to clean up waste in the entire supply chain, which is why it's more than just the original product defects clean-up nowadays.
It is hoped that the above will give you a deeper understanding of what is six sigma and what it is not. Consider it to be the gold standard for business analysis. It takes effort, but the long term savings to the company are spectacular.