
Six Sigma and More:
David Schwinn reflects on Deming’s insistence on
onjob training.
by David R. Schwinn

Considering the farreaching impact of W. Edwards Deming’s approach
to management, it is instructive to return to Deming’s 14 Points for
Managers and what he called “deadly diseases” in organizations.
“Institute training on the job,” Deming’s Point #6 is the focus of
this column.
In the mid1980’s Mike Cleary and I attended a conference for
statisticians organized by George Washington University. It was titled
something like “Statistics for Statisticians” and taught by W. Edwards
Deming. The room was filled, mostly with college instructors in
statistics. I was overwhelmed at the end of the conference by the large
number of participants who approached Deming, confessing that they had
spent their whole careers leading their students astray.
What was it that brought those instructors to that conclusion? During the
conference, Deming had stepped back, examined underlying theories of
statistics and offered a “new” branch of statistics. In his
presentation, he did not introduce new information. He simply framed what
they already knew in a profound, new way.
Deming reexamined the traditional mainstream approaches, descriptive and
inferential statistics. Descriptive statistics helps you understand a
group of items if you can count, measure, and/or operationally define all
of the items in the group. If you want to understand the group by only
counting, measuring, and/or operationally defining a sample of the group,
then you must use inferential statistics. Both of these approaches help
you understand what you have. The methods can also help you understand how
the group compares to preset standards. They can help you understand how
one group compares to another. They can even help you make a decision
about what to do with any of the groups about which you have this
knowledge. Descriptive and inferential statistics are extremely powerful
tools for helping you understand and make decisions about what you have.
Unfortunately, they have very little value in helping you with what you
don’t have. And understanding what you don’t have and making decisions
intended to affect the future is the job of most managers and, for that
matter, many people who are not in traditional management positions. Most
statisticians understand this. Dr. Deming helped the seminar participants
understand that by focusing on these approaches in the classroom, most of
THEIR students did not comprehend the limitations of what they were
learning. Their students went out to the world of work and made decisions
using descriptive and inferential statistics erroneously.
Dr. Deming suggested that a much more powerful approach was to use
analytic statistics, a phrase, I believe, he invented. Analytic statistics
is the use of control charts. Dr. Deming reviewed that analytic statistics
permit you to examine how a system behaves over time. If you understand
how a system behaves over time and it is statistically stable, you can
expect that it will continue that behavior unless a significant change is
made. You even have a superficial understanding of when and what changes
can be considered significant. Without that knowledge, however, a
person’s ability to know if they will make or have made significant
change is grossly impeded. The bottom line is that, without the use of
analytic statistics, you cannot know, in a modern scientific sense, if
what you did or did not do made any difference. Unfortunately, that lack
of knowledge still does not keep the majority of leaders and managers from
claiming that knowledge and acting as if they have it. That is the
understanding that devastated the students in that conference.
Now, what has all that got to do with training and Six Sigma? I believe
that Six Sigma embraces the need for training in much the same way that
Dr. Deming embraced the need for training except in the area of analytic
statistics. I understand that Six Sigma embraces analytic statistics but I
believe that the difference in the power for improving systems among the
three statistical approaches is not well understood. It is useful to
remember that Dr. Deming thought that some of the descriptive and
inferential statistical tools, such as Ftests and ttests, which are
commonly taught as part of Six Sigma, were a waste of time for those
interested in improving systems.
As always, I welcome other thoughts on training on the job and Six Sigma. I'm at support@pqsystems.com
