Statistics

The Man of La Mancha never got to the unreachable goal—and if you’re being judged by overall equipment effectiveness (OEE), then your manager may also be dreaming an impossible dream. This column will look at problems associated with the use of OEE values.
OEE is a value often…

In last month’s article, “ANOVA and the Process Behavior Chart,” we saw how both techniques use the same basic comparison to answer completely different questions. Here, we’ll look at a case history where both techniques were used.
A physical property of a mass-produced item was…

Recent labor relations controversies and ongoing arguments about the minimum wage have raised questions as to how a supply chain should share the utility it produces.
If we ask the wrong question, however, we’ll get the wrong answer. “What is a fair share?” asks how a supply chain…

When Sir Ronald Fisher created the analysis of variance (ANOVA) in the 1920s, he extended the two-sample t-test to allow the comparison of k sample averages. During the same time period, Dr. Walter Shewhart was creating the process behavior chart. So it should be no surprise that both techniques…

Managers are commonly fed a diet of report-card data. These data have usually been aggregated into summaries, averages, and totals to characterize the big picture. As useful as such summaries can be, they can also be an obstacle to an effective analysis. Here, we’ll learn how to avoid this…

Time: We all have a sense of it, an innate feel for it. We see it and use it every day. If you’re like me, the first thing you do in the morning is check the time on your phone to see if you need to get out of bed or if you can close your eyes and catch a few more z’s.
Once you’re…