In an effort to better understand the nuances of SixSigma, I’m going through a book called "The Six Sigma Way" by Pande, Neuman and Cavanagh.  It’s a well-written book and offers a good insight into the methodologies of Six Sigma and their application in industry. 

Here’s an interesting extract on the difference between "99% success" and "SixSigma success" :

1. For every 300,000 letters delivered :

With 99% – 3,000 misdeliveries
With SS   – 1 misdelivery

2. For every 500,000 computer restarts :

With 99% – 4,100 crashes
With SS   – < 2 crashes

3. For every 500 years of month-end closings :

With 99% – 60 months would not balance
With SS   – 0.018 months would not balance

4. For every week of TV broadcasting :

With 99% – 1.68 hours of dead air
With SS   – 1.8 seconds of dead air

That’s the difference between 99% perfect and 99.9997% perfect!