Lean
''Lean is a business philosophy used to continuously identify, reduce and eliminate the wastes from all walks of business''. (Source: The Six Sigma Way, Tata Mcgraw Hill)
Lean concept is used to identify Non-value adding activities in the processes and strategically remove it from the end-to-end value stream.
Six Sigma
''A flexible and comprehensive system for achieving, sustaining and maximizing business success''. (Source: The Six Sigma Way, Tata Mcgraw Hill)
It is uniquely driven by close understanding of customer needs, disciplined usage of data & facts, statistical analysis and diligently attention to managing, improving, and re-inventing the business processes.