Difference between Lean and Six Sigma

Six Sigma Benefit 

Eliminate Variability & Improve Quality

•Data Collection/Measure Analysis

•DMAIC Project Flowchart

•Tie Project to Business Metrics

Lean Benefit 

Identify & Eliminate Process Waste

•Improve Process Flow and Efficiency

•Develop low cost, simple, agile processes

Comparison of Six Sigma and Lean


Six Sigma : Reduce variation / Lean : Reduce Waste

Six Sigma : Six Sigma Quality (3.4 DPMO) /  Lean : Speed (velocity)
Main Saving

Six Sigma :  Cost of Poor Quality  / Lean : Operating Costs

Learning Curve

Six Sigma: Long  /  Lean : Short
Project Selection

Six Sigma: Various approaches / Lean :  Value Stream Mapping
Project Length

Six Sigma  : 2-6 Month / Lean : 1 week -3 month
Driver Data Demand

Six Sigma: Complexity  /  Lean : High Moderate

When to execute Lean 

If major business problems are:
•There seems to be a lot of wastes
•There is a need to minimize inventories and redundancies
•There is a need to improve work flows
•There is a need to speed p processes
•There are human mistakes

Then, Lean techniques can be used to:
•Eliminate wastes
•Simplify processes
•Increase speed
•Improve flows
•Minimize inventories
•Mistake proof processes

When to execute Six Sigma

If major business problems are:
•There are quality issues
•There is excessive variation
•There are complex problems
•There are challenging root cause identifications
•There are numerous technical considerations
Then, Six Sigma techniques can be used to:
•Minimize variation
•Apply scientific problem solving
•Utilize robust project chartering
•Focus on quality issues
•Employ technical methodologies