I got a message from a reader of my book Measures of Success: React Less, Lead Better, Improve More. The questions were: “I entered data from Press Ganey patient satisfaction responses (12-month running totals) and since the numbers were so close to each other, the PBC showed a bunch of data points outside the upper/lower process limits.  When I changed the limits to +- 3 sigma, this issue disappeared.  Have you run into this issue … Continue reading [Updated] Reader Question: Why are There so Many Data Points Outside of the Limits?