Almost seven years ago, Quality Digest presented a short article by Matthew Barsalou titled “A Worksheet for Ishikawa Diagrams.” At the time, I commented concerning enhancements that provide greater granularity. Indicating that he would probably have little time to devote to such a project,...
The computation for skewness does not fully describe everything that happens as a distribution becomes more skewed. Here we shall use some examples to visualize just what skewness does—and does not—involve.
The mean for a probability model describes the balance point. The standard deviation...
Corrective action and preventive action (CAPA) is probably the most important process in any quality management system because so much else depends on it. This includes not only its traditional role as a response to defects, nonconformances, customer complaints, and audit findings, but also outputs...
The cumulative sum (or Cusum) technique is occasionally offered as an alternative to process behavior charts, even though they have completely different objectives. Process behavior charts characterize whether a process has been operated predictably. Cusums assume that the process is already being...
