Control chart example

This example was redesigned from the Wikimedia Commons file: Xbar chart for a paired xbar and R chart.svg. "Example xbar chart for a process that experienced a 1.5σ drift starting at midnight." [commons.wikimedia.org/wiki/File:Xbar_chart_for_a_paired_xbar_and_R_chart.svg] This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.[creativecommons.org/licenses/by-sa/3.0/deed.en] "A control chart: process output variable is modeled by a probability density function and for each statistic of the sample an upper control line and lower control line are fixed, when the statistic moves out of bounds, an alarm is given and possible causes are investigated. In this drawing the statistic of choice is the mean and red points represent alarm points." [Operations management. Wikipedia] The "Control chart example" was created using the ConceptDraw PRO software extended with the Seven Basic Tools of Quality solution from the Quality area of ConceptDraw Solution Park.