| Lean Six Sigma has grown out of the realization that | | | | with a Lean approach. It never makes sense to take a |
| the two systems, Lean Manufacturing and Six Sigma, | | | | DMAIC approach when the ideal solution is evident. |
| can not only co-exist, but actually complement each | | | | Although both are methods for Continuous |
| other. | | | | Improvement, Lean tends to be incremental in nature |
| There are many ways of approaching this "merger". If | | | | with small gains adding up over time to great gains, |
| the problem is complex and requires careful definition | | | | whereas, Six Sigma is a breakthrough method looking |
| and analysis, the DMAIC approach and the Six Sigma | | | | to make significant changes to the underlying process, |
| statistical tools should be used. Depending on the | | | | resulting in major quantifiable impacts. |
| problem, and the process, a VSM (a Lean tool) along | | | | While Six Sigma's main focus is defect reduction by |
| with SIPOC and VOC (6 Sigma tools) can be used | | | | reduction in process variation, Lean focuses on waste |
| during the Define phase to fully understand the | | | | elimination and flow. However, Lean also uses "Poke |
| problem. | | | | Yoke" or mistake proofing to prevent defects. So you |
| As waste is identified, the type and complexity of the | | | | can see how they complement each other. |
| problem will dictate whether to continue to follow a | | | | In some companies, quotas are given to Belted |
| DMAIC approach for a specific problem or whether a | | | | employees to produce a number of Six Sigma |
| Lean Tool is more appropriate such as a Kaizen | | | | projects and projects that can be easily handled by |
| Event, 5S implementation, production cell, etc. In general, | | | | other means are called "Six Sigma" to comply with the |
| if the problem involves organization, lack of flow or | | | | expectation. I have also seen some large companies |
| speed of delivery, most likely a Lean tool would be | | | | that have a Lean Department and a Six Sigma |
| used. Lean solutions are meant to be low cost | | | | Department. That separation does not make sense |
| solutions; Six Sigma evaluates solutions based on cost | | | | and conflicts can arise. A good Lean Transformation |
| benefit analysis. | | | | involves all employees, whereas, Six Sigma is often |
| There is a difference in problem solving attitude. Lean | | | | limited to technical and management people. |
| has a "Just do it" approach. An "imperfect Lean | | | | The combination of Lean and Six Sigma is very |
| Solution is better than no solution". | | | | powerful. Any conflicts between the methodologies |
| Six Sigma, on the other hand, is more methodical and is | | | | should be easily resolved once their unique |
| best used for the more complex projects requiring | | | | characteristics are understood. |
| careful analysis. The "low hanging fruit" are often dealt | | | | |