As a developer and instructor for Villanova University’s LSS online program (www.villanovau.com), I get a lot of questions about how lean and Six Sigma work together. This topic is treated in the first chapter of a new book I co-authored, LSS Primer, published by the Quality Council of Indiana (www.qualitycouncil.com), a summary of which follows.
A simple model to understand a new paradigm–the LSS continuum.
Here is a simple way for anyone to think about lean and Six Sigma on a continuum–and why LSS is a better paradigm. Business problems can be thought of in two contexts that help us think about which tool, lean or Six Sigma, might be best in a given situation. Consider the types of problems your organization routinely faces. Do the following statements seem to be true?
There seems to be a lot of waste. There is a need to focus on taking time out of processes and speeding them up―reducing inventory, effort, and redundancies. This includes improving workflows and value streams and solving problems that seem to be driven by people issues. The many opportunities for mistakes and/or human inspection and decisions seem to be a key root cause of the problems.
If these statements tend to be true, then a lean approach has strong promise on the left side of the continuum. Lean tools typically work on waste elimination, increased speed, less inventory, better flow, consumption-based replenishment and reduction of "noise" in processes.
On the other hand, think again about your organizational challenges. Do they exhibit the following attributes?
There seems to be a lot of trouble with quality and variation. Problems are difficult to understand.
The issues defy easy understanding; they are complex and technical in nature. In these cases, a variation of process results is the enemy, scientific solutions are required, and finding true root causes is a huge challenge.
If these strongly correlate with your problems, then a Six Sigma approach has strong promise, which we will place at the right side of the continuum. Six Sigma tools work to eliminate variation and provide a laser focus on quality and scientific problem-solving tools. Six Sigma also offers DMAIC (Define, Measure, Analyze, Improve and Control)–a robust project chartering and management process to guide you on your way.
All of the aforementioned discussions assume that our organizational challenges fit neatly in one category or the other. Now I ask you to reflect: is it not true that most of your organizational issues are actually some combination of both sets of these issues? Most of the time, the answer will be yes to a greater or lesser degree, which brings us back to our continuum. This is where we recognize the LSS reality: LSS is the fusion of Lean and Six Sigma. A way of thinking―it is holistic, synergistic and open to innovation.
The business case for Lean Six Sigma
The trick for executives and practitioners going forward is to think about and understand the perils of a "single tool" mentality. The old saying about narrow views can be summarized as: "If the only tool in your bag is a hammer, all your problems look like a nail." We might use a hammer to get that threaded screw through that wood, but we probably won’t be happy with the results or the time and energy it takes to get the job done.
What is needed is a clear-headed and holistic line of thinking going forward. Are our problems clearly to the left or right side of this continuum? Or is it really a case of diagnosis and understanding our issues one at a time? Is the issue really a combination of both categories of problems?
In most cases, when we examine a specific issue, we should find ourselves sliding to the left or the right on the continuum in terms of the tools to apply. This is perfectly ok. LSS is a new paradigm requiring a broader view of improvement approaches – a significant differentiator for early adopters.