The Statistics of Six Sigma

The Statistics of Six Sigma are quite simple.  This topic is often complicated by crazy equations and debates about shifts, but the essences of Six Sigma Statistics is very basic.  The understanding of these statistics is easy to explain and understand so that everyone can have an appreciation for it's benefits.
The Six Sigma level of quality is simply based on the fact that the variation within a process is minimize to the point that the average variation is one sixth that of the specification range on each side of the average.  An example of this would be if the average ship time was 3 days and the customer expected the shipment between 1 and 5 days, the process variation about the mean would have to be less than .33 days.  At this level of quality, only 3 defects per million shipments would be experienced by the customer.
Imagine if you were able to go throughout one day and experience this level of quality.  It's easy to see that dealing with processes that perform correctly 99.9997% of the time would make life easier.  That is the essence of "Six Sigma" and the statistics of Six Sigma, making "Life Easier". 
That being said, making life easier can provide a very large competative advantage for world class corporations competing for your business.  This would be the reason for all the activity around Six Sigma