I-MR (Individual-Moving Range) Chart

A common control chart, it is a statistical tool that measures the performance of a process to see how "in control" it is. It does so by plotting individual data points from the process plus the distance between each data point (i.e., its moving range) and evaluates the capability by comparing these data points with the lower/upper control limits (LCL/UCL) for the process. A series of tests can be applied to the control chart to identify special causes.
Related StatStuff Videos: 
   -Section 8-Control Phase, Lesson #4 - Control Charts: I-MR Chart
   -Section 5-Measure Phase, Lesson #16 - Testing for Special Cause Variation