Most often when we think of a wheel, it’s in the context of transportation, one of the more obvious and ever-present of the 7 wastes in lean. In fact, the first likely use of a wheel and axle was not for transport but for processing—actual work.

Here is an article I wrote 10 years ago, recently resurrected from the lost letter file. I can’t remember why I wrote it or for whom. Originally titled, “What is Kaizen?” the article still resonates with me as I hope it will with you.

If you are reading this, you are likely human. Congratulations; I’m human, too.

What can be done when a test is destructive? How do we characterize measurement error? How can we determine if a test method is adequate for a given product or application? How can we check for bias?