Six Sigma at many organizations simply means a measure of quality that strives for near perfection. Six Sigma is a disciplined, data-driven approach and methodology for eliminating defects in any process - from manufacturing to transactional and from product to service.

One may have a brief but detailed overview of this concept and its method at http://www.induction.to/six-sigma/ which explains very precisely the review of six sigms technique & its approach.

Regards

Priyanka