Lean Six Sigma is a powerful methodology which complements both speed and excellence together. Lean will get you to response to your customers faster by elimination of the non-valued added activities in your business process while six sigma ensures your process is defect-free.  

Six Sigma at many organizations simply means a measure of quality that strives for near perfection. Six Sigma is an integrated, disciplined proven approach for obtaining measurable financial results for any organization .Six Sigma is a disciplined, data-driven approach and methodology for eliminating defects (driving towards six standard deviations between the mean and the nearest specification limit) in any process -- from manufacturing to transactional and from product to service.  

Bpmi’s Enterprise Lean Six Sigma provides a balance approach to simultaneously reduce complexity and increase reliability.  The statistical representation of Six Sigma describes quantitatively how a process is performing. To achieve Six Sigma, a process must not produce more than 3.4 defects per million opportunities. A Six Sigma defect is defined as anything outside of customer specifications. A Six Sigma opportunity is then the total quantity of chances for a defect.