Evaluating the Measurement Process or EMP, is a technique based on process behavior charts that allows you to discover what is happening in the data more efficiently. Designed under the guidance of statistician, author and quality expert Donald J. Wheeler, the EMP study begins much like a gage reliability & reproducibility study, but then immediately places the data on an average and range chart. An emphasis on the qualitative assessment of the data prior to computing estimates of the various quantities can result in a more informed and useful analysis than that obtained by a computational approach alone.
While the EMP approach can be adapted to many different data structures and collection schemes, this paper illustrates the basic EMP study using the same data collection strategy used in a gage R&R study.