## Metadata - Author: [[michel-baudin|Michel Baudin]] - Full Title:: The Math Behind the Process Behavior Chart - Category:: #🗞️Articles - Document Tags:: [[A chart from the 40s is all you need|A Chart From The 40s Is All You Need]], - URL:: https://michelbaudin.com/2019/03/02/the-math-behind-the-process-behavior-chart/ - Finished date:: [[2024-02-20]] ## Highlights > The readers are discouraged from worrying their heads with the provenance of these numbers, and the closest they get to an explanation is a reference to a table where such coefficients are kept, and this table was generated by a higher authority. No further explanation is found in the books I have seen by Douglas Montgomery, J.M. Juran, or Don Wheeler. ([View Highlight](https://read.readwise.io/read/01hq2q1kjs6tbqt3dgdv26vavk)) > This derivation confirms that the published coefficients are based on the assumption that the monitored variable is Gaussian. Of course, it doesn’t *prove* it but it is highly unlikely that any other distribution would produce the exact same coefficients. ([View Highlight](https://read.readwise.io/read/01hq2q4gmc73zdn7dvfadssfax))