Uncommon Sense: Dueling Paradigms
Lean manufacturing and Six Sigma have both been trumpeted as potential saviors of U.S. industry. Each has its share of documented successes, but many companies seem to struggle with which approach is best. In my view, neither lean nor Six Sigma alone is an adequate umbrella under which to lead your organization forward; both lean and Six Sigma are needed to compete in today's markets.
Lean is focused on eliminating waste-any activity that does not add value to a product or service. Lean is well-documented, but not always successfully applied, especially if you cling too precisely to the tools of lean, rather than the underlying principles of reducing lead time and process variation. Lean views process variation as waste and attacks it with tools such as schedule leveling and mistake proofing. Much of the path to Six Sigma performance is actually paved with lean tools such as these. And like Six Sigma, lean emphasizes performance metrics.
Six Sigma is a great tool for reducing variation and improving quality, if you can isolate the variation and quality problem you want to study. We have seen a Six Sigma project undertaken to analyze and reduce setup and cycle time variation in an assembly process, both of which are traditionally areas where lean would have been applied. Conversely, we have seen kaizen teams struggle to address variation in a complex process, where Six Sigma would be a much better approach. In the setup reduction project, six months of data collection did not reduce setup times, because the team never went to the shop floor to study the work process, as you would in a kaizen event. When a setup reduction event was actually run, the baseline data proved very useful and the Six Sigma control plan helped standardize the new process.
Generally, I believe lean is the best program to start with. Its focus on waste reduction and quick implementation clears the way to defining complex problems that require the Six Sigma approach. Our most progressive clients employ lean, Six Sigma and other process improvement concepts under a continuous improvement umbrella.
Regardless of the technical tool set, any improvement effort is also a change effort, which unfortunately must be implemented with and through the people in your organization. I say "unfortunately" because we all know how much we welcome change personally, and resistance to change is what limits the impact of many well-defined improvement initiatives. Therefore, organizational change management must be addressed along with lean, Six Sigma and any other improvement methodology to sustain change and build a culture of continuous improvement.
Which improvement methodology is the best, or should be the lead program, isn't the issue. Avoiding this trap can be a significant waste reduction step in itself. Organizations must bring a robust tool set to the process improvement game to succeed and-more importantly-know how and where to use the basic tools. In our experience, lean clears away the brush so you can focus on true process variation problems with Six Sigma techniques. Other tools that complement the simplification and variation reduction themes can be used with both lean and Six Sigma.
If it was easy, everyone would be doing it well. But it isn't easy, which is why some organizations thrive while others struggle with similar approaches. Be one of the winners. Have a big tool kit, and know how and where to apply the tools. Most importantly, know how to sustain the changes they drive in your business.