What are the differences between lean management and six sigma?

While lean focuses on minimizing process waste and eventually reducing lead times, Six Sigma focuses on minimizing variations and improving the quality of the product. Nevertheless, there are many common tools between the two systems today. One should start with lean before six sigma in the implementation.

six sigma  is a methodology that combines process speed with quality. To become a truly more efficient and effective organization in terms of operations and business processes, you must have both Lean and Six Sigma methodologies; having one without the other ultimately results in process destruction.

Lean, itself, focuses on speed. It emphasizes reducing the amount of time between activities, events, and cycles.  The shorter the cycle time, the more cycles you can complete in a given amount of time. Lean also identifies areas where process waste and bottlenecks can be eliminated.