All Features
Bruce Hamilton
The last few weeks for me have been all things Shingo, including a presentation at the Shingo Institute’s International Conference three weeks ago in Provo, Utah, followed by four days of Shingo Institute workshops at Vibco in Richmond, RI. Questions at both events about assessing for enterprise…
Patrick Runkel
It’s usually not a good idea to rely solely on a single statistic to draw conclusions about your process. Do that, and you could fall into the clutches of the “duck-rabbit” illusion shown below.
If you fix your eyes solely on the duck, you’ll miss the rabbit—and vice-versa.
If you’re using…
Brian Maskell
It is vitally important for lean people to know nothing when working on improvement. This sounds like a crazy idea, but it is another 100-percent turnaround from traditional management thinking.
To do this, it’s necessary to do three things: • Understand how lean thinkers go about radically…
Rip Stauffer
Recently, in one of the many online discussion groups about quality, Six Sigma, and lean, this question was posed: “Can X-bar R and X-bar S be used interchangeably based on samples size (n) if the subgroup size is greater than one and less than eight?” Answers varied, of course.
In some of these…
Dawn Keller
Generally speaking, I have a problem with authority. I don’t like being told what to do or how to do it. I’m not proud of that.
I recall debating with my high school trigonometry teacher regarding the value of the homework “process”—specifically in those situations where the student in question…
Jens R. Woinowski
As you browse through lean management pages on the Internet, you may have seen reports on companies having little success with lean, or comments about how misunderstanding lean can lead to bad consequences. From time to time I can sense the level of frustration from those comments, and I…
Eston Martz
Last week I attended the American Society for Quality’s World Conference on Quality and Improvement in Nashville, TN. The ASQ conference is a great opportunity to see how quality professionals are tackling problems in every industry, from beverage distribution to banking services.
Given my…
Steve Daum
The ability to make predictions has always been rewarded. Statistician Donald J. Wheeler says that “prediction is the essence of business.” With growing bodies of data and good analytical models, our predictions are getting better.
The statistical models and algorithms behind prediction can be…
Donald J. Wheeler
Parts per million (ppm) is part of the language of Six Sigma. It pervades the sales pitch and is used in all sorts of computations as a measure of quality. Yet what are the rules of arithmetic and statistics that govern the computation and usage of parts per million? To discover the answers read…
Bruno Scibilia
The Cp and Cpk are well-known capability indices commonly used to ensure that a process spread is as small as possible compared to the tolerance interval (Cp), or that it stays well within specifications (Cpk). Yet another type of capability index exists: the Cpm, which is much less known and used…
Quality Transformation With David Schwinn
Let’s begin with yet another example of a lack of understanding of the Perversity Principle, this one from a recent The Times of India report.
“Authorities in India have reportedly arrested some 300 people and expelled 600 students in connection with a massive cheating scandal in the northeastern…
Bob Emiliani
Regular readers of my column, as well as my Twitter and LinkedIn feeds, will know that in recent months I have posted many critiques on various aspects related to the products, promotion, and practice of lean management. Why now? The reason is that 20 years of engagement in lean offers the unique…
Michelle Shemo
As a member of Minitab’s technical support team, I get the opportunity to work with many people using design of experiments (DOE).
People often will call after they’ve already chosen their design, run the experiment, and identified the important factors in their process. But now what? They have…
Bruno Scibilia
Suppose you have designed a brand-new product with many improved features that well help create a much better customer experience. Now you must ensure that it’s manufactured according to the best quality and reliability standards so that it gets the excellent long-term reputation it deserves from…
Patrick Runkel
Right now I’m enjoying my daily dose of morning joe. As the steam rises off the cup, the dark, rich liquid triggers a powerful enzyme cascade that jump-starts my brain and central nervous system, delivering potent glints of perspicacity into the dark crevices of my still-dormant consciousness.…
Quality Transformation With David Schwinn
Last weekend we took all 16 members of our family on a ski trip. It was amazing, and we are incredibly lucky. We haven’t done such a thing in 17 years, when our first grandchild, Claire, was only one month old. Life gets complex and 17 years fly by.
That experience reminded me of work my wife,…
Davis Balestracci
In my last column, I discussed how even a well-designed study with a statistically significant result doesn’t necessarily mean viability in the real world. Post-study, one must study the manifestations of variation on the result in any environment in which the result is applied—and each…
Joel Smith
I typically attend a few lean Six Sigma conferences each year, and at each there’s at least one session about compensating belts. There are any number of ideas for how to do so, but they commonly include systems that provide a percentage of savings as a portion of pay, or provide a bonus for…
Quality Transformation With David Schwinn
‘From laughing tots in Haitian preschools to inner-city gang members to top executives in global corporations, people everywhere are gathering in circles. These circles are generating trusting relationships among people with long histories of antagonism; promoting healing among people suffering…
Davis Balestracci
I have evolved to using fewer, simpler tools in my consulting and have never been more effective, as I commented upon in my last column. It made me ponder the relevance of much of what I learned in my master’s statistics program. Thinking of the most basic concepts, I decided to look up what the…
The purpose of this article is to point out a problem when using percentages for subgroups over time, or for members in a larger group, where the size of the denominator varies and probabilities are being estimated. Also to introduce a solution: adjusted p-chart scores (APC), a new way to score or…
Patrick Runkel
If you’re not a statistician, looking through statistical output can sometimes make you feel a like you’ve wandered into Alice in Wonderland. Suddenly, you find yourself in a fantastical world where strange and mysterious phantasms appear out of nowhere. For example, consider the T and P in your t…
Donald J. Wheeler
Whenever the original data pile up against a barrier or a boundary value, the histogram tends to be skewed and non-normal in shape. Last month in part one we found that this doesn’t appreciably affect the performance of process behavior charts for location. This month we look at how skewed data…
Thomas R. Cutler
This is the last in a series about how lean manufacturing has affected the people and the companywide culture at Hytrol Conveyors, a designer and manufacturer of advanced conveyor systems. As described in part 1 and part 2, dozens of interviews were conducted with a wide range of employees at the…
Barbara A. Cleary
When my mother looked at the prices of new hats, studied their features, and then went home and tried to remodel her old hat with feathers or lace to look like those fancier models, I saw the value of doing things yourself—for my mother, an attitude perhaps shaped by her own parents and their…
