In this first installment of a three-part series, we explore a blog item published last week (Six Sigma: Is It Greek to You?), taking a look at Six Sigma overall, the joys of statistics, and whether or not any philosophy or methodology should be applied across an enterprise.

While she doesn’t present herself as an all-knowing expert, my daughter Lauren is a Six Sigma Black Belt who works for a defense contractor. Father and daughter working together on the IMT Blog. Is this the embodiment of family values or what? Hope you enjoy the Q&A… –Mark Devlin

Quality experts seem to define Six Sigma from a perspective that’s at least one step back from the battlefield. You’re in the trenches as a Six Sigma Black Belt. How do you define Six Sigma?

I define Six Sigma as a data-driven methodology that people use for implementing change. It’s a statistical way to take a process, analyze it, and figure out how to reduce the number of defects, improve quality and customer satisfaction. Six Sigma also gives you the statistics, or data, justify required process changes. Later on, those statistics will reveal whether or not the process methodology changes have actually worked.

We’ve talked about DMAIC (Define, Measure, Analyze, Improve, Control) and DFSS (Design For Six Sigma). What is RIE (Rapid Improvement Event)?

It’s a way to fast-track DMAIC or DFSS implementations. If you’re going through DMAIC, for example, you would spend at least four days working through all the phases. In RIE, a person is typically dedicated to go through the various phases to quickly Define, Measure, Analyze, etc., instead of spending only a couple of hours per week on these tasks in a group setting.

Generally, the DMAIC methodology can take six months to complete if you have six people working on it, and by that I mean five Green Belts and one Black Belt at 20 percent of their time. DFSS will take much longer, typically a year, at those same resource levels. Also, that’s by the book. [Actual mileage may vary.] RIE gets either DMAIC or DFSS done more quickly.

It’s mentioned that DMAIC may turn into DFSS when a process requires a complete overhaul. Is DFSS also used at the beginning of the new product or process?

The purpose of DFSS is to be used at the beginning. But it can also be used to completely revamp an existing process. If you identify that you need to restructure a whole process, then you go to DFSS. If you know from the beginning that you don’t have a process at all, you then also use DFSS.

Some people seem to criticize the statistical standard of Six Sigma. Comments?

Statistics are statistics. The statistics that are used in Six Sigma are no different than the statistics that people learn at Harvard. We’re using control charts and all types of data points, for instance. We’re using tried and true statistical analysis techniques that are not specific to Six Sigma. For example, you have an upper limit and a lower limit on a control chart. Anything in-between those is usually a common-cause variation of your process. Anything that goes outside of those upper and lower limits is a special cause variation. These things aren’t specific to Six Sigma. They’re things that you would look at in any statistical methodology.

Is it wrong to apply any single standard across an enterprise?

Generally, yes. Six Sigma is meant to be used as a tool. In many organizations, CMMI [Capability Maturity Model-Integration] is applied along with Six Sigma. Such a combination can be very positive. Six Sigma is a tool that defines how you can do it. CMMI (a model of best practices, mostly in software or systems organizations) tells you what you need to do — what you need to focus on in each area of the process.