Difference Between a Project Program and a Training Program

Don't get me wrong:  Good training in Six Sigma is a good thing.  But if you structure a corporate program as a training program rather than a projects program, you leave a lot of money on the table.

A Six Sigma program structured around projects measures itself by the number and quality of projects completed.  That is the thing that it reports to management.

A Six Sigma program structured around training measures itself by the number and type of trained "belts" it produces.

You can show the effects of projects on your Income Statement and Balance Sheet.  It's much harder to show the effects of just training.

Normality is Overrated

People are often overly concerned about having normally distributed data.  There are a few cases where having normally distributed data is important.  There are many more cases where distribution does not matter very much.  It's usually much more important that the data are drawn from a stable and predictable (same as homogeneous, or in control) process, but nobody seems to pay much attention to that.

Choosing the Normal Distribution to represent your data is an assumption.  Your choice of assumptions does not add information to the data.

If your data are stable and predictable, you can pretty well depend on the following rules holding true, regardless of how the data are distributed:

60-75% of the data will be within plus and minus one standard deviation of the mean.

90-98% of the data will be within plus and minus two standard deviations.

99-100% of the data will be within plus and minus three standard deviations.

In view of this, the conventional 68%, 95%, and 99.7% numbers for the Normal Distribution are a modest refinement of the general case.

Dr. Don Wheeler has another excellent article posted at Quality Digest, explaining how to use I-MR (he calls them XmR) charts to evaluate the precision and bias of a measurement system.  You can read his treatise here.

There are several tools for evaluating measurement systems, including Gage R&R and Intraclass Correlation Coefficient.  None are quite as simple and elegant as the one Don discusses.

Here is Don, quoting Churchill Eisenhart at Nation Bureau of Standards, back when that is what the organization was called:

Until a measurement process has been "debugged" to the extent that it has attained state of statistical quality control, it cannot be regarded, in any logical sense, as measuring anything at all.

Six Sigma Project Example

Sometimes the simplicity of Six Sigma gets buried in the complexity of the tools.  Here's an uncluttered video that shows how a typical Six Sigma project might unfold.  Of course, it's all a lot easier with the QuikSigma software, which you can learn about here.

Using Individuals and Moving Range Charts to Fact-Check the News

One of the strengths of I-MR charts is that they put data in context.  Here's an interesting example where a major news outlet failed to view data in context, and ended up publishing an article with exactly the wrong conclusion.

Six Sigma Tool Example: Individuals and Moving Range Charts

Individuals and Moving Range (I-MR) charts are one of the most insightful tools you can learn.

Here is a short 4 minute video that shows some of their uses, and also shows some of the errors that are commonly taught.  It's best viewed at 720p resolution.