3M is another pioneer in the application of Lean Six Sigma. When Jim McNerney took over as CEO of the company in 2001, the former GE executive quickly helped drive a Lean Six Sigma program throughout the company.
“Lean Six Sigma always starts by defining value from the supply chain from the eyes of the customer,” says Paul Husby, a former VP of Supply Chain Services at 3M. “Every business has either an explicit or implicit strategy and needs the operational supply chain to provide specific performance to support that strategy. Lean Six Sigma has a primary goal of significantly improving operational excellence, and should also greatly improve a company's competitive advantage with key customers and markets.”
There are several principles that drive the strategy of bringing Lean and Six Sigma together:
- Lean cannot bring a process under statistical control
- Six Sigma alone cannot dramatically improve process speed or reduce invested capital
- Both enable the reduction of the cost of complexity, but in complementary ways
In the past, Lean and Six Sigma have at times been viewed almost as rival methodologies, with some companies choosing one or the other as their primary improvement vehicle. With Lean Six Sigma, that false conflict can be formally removed, and companies can benefit from the best of both approaches.
The two methodologies can interact and reinforce one another, and there is much evidence that total improvements in a process is larger if Lean and Six Sigma are implemented together.
“The opportunity is to reduce the variability in value-adding processes,” said SCDigest editor Dan Gilmore. “Lean should eliminate the non-value added process steps, and then Six Sigma can be applied to tighten up the execution of those processes.”
So, from a Lean perspective, what Six Sigma adds is the ability to reduce process variability. From a Six Sigma perspective, what Lean adds is often greater process and cycle time velocity, as well as lower operating costs. It can also be said that Lean focuses on reducing Time variability, while Six Sigma focuses on reducing Process variability. Lean tends to generate more “Quick Fix” solutions, while Six Sigma takes a more “Root Cause” approach.
It is also possible to think of applying Six Sigma principles at the “pursue perfection” stage of one popular six-step Lean model.
Some companies are taking the concept even further, adding in Eli Goldratt’s Theory of Constraints (TOC) methodology as another tool, usually front-ending TOC before both Lean and Six Sigma. This three-way combination is sometimes referred to as TLS (TOC, Lean, Six Sigma).
Companies that have focused on either Lean or Six Sigma as a primary strategy to the exclusion of the other, or that use both but as very separate tools, should consider whether there is opportunity to deliver better results from a Lean Six Sigma strategy.
Do you think combining Lean and Six Sigma is usually the best total approach? Or are they better used separately to solve different problems? Let us know your thoughts at the Feedback button below.