Ott’s Rules

Ellis Ott was a statistician at Rutgers. He wrote a well known book entitled Process Quality Control in which (among other things) he laid out some rules for those wishing to establish process control. They were:

1. Use Data

That is, no more “gut feel”. Or, “I’m 90% confident in this one…” If there is data available try to use it.

2. Use Graphs

By which he meant to present data visually for best understanding.

3. Plot Data in Time Sequence

Unless data is plotted over time, it loses it’s context. Data without context is usually meaningless or, worse yet, misleading.

Process Quality Control was written in its original edition (including the above) in 1975. That’s 30 years ago. This very sage advice is largely ignored even today. Business leaders look at charts that are columns of numbers. The numbers are rarely presented over time or graphically and almost never with context. Most of it is useless. But, unfortunately, it’s often used.

No wonder they are not competitive.

W. E. Deming used to say, “Perhaps we are being ruined by best efforts… everyone doing his best, doing the wrong things. Best efforts aren’t enough. Knowledge is required. There’s no substitute for knowledge.”