It is time to replace the average/range method and ANOVA method for Gage R&R studies. Evaluating the Measurement Process (EMP) is a collection of techniques that allows you to discover much more about your measurement process than if you just use those traditional techniques. EMP has been developed over the years by Dr. Donald J. Wheeler.
Measurements tell us many things. They tell us if a product is within specification, if we met our goal, if we are staying the same, if we are improving, if we are getting worse, etc. What makes a good measurement process? This is essentially asking the following question:
What does it take for us to trust our measurement process?
This is the final blog in a four-part series on Gage R&R studies. The first blog addressed what a gage R&R study is. The second blog addressed Gage R&R studies and process variation and determine the % of total variance due to the measurement system. The third blog examined how good your measurement system is using an Evaluating the Measurement Process (EMP) classification developed by Dr. Donald Wheeler.
You just completed your ANOVA Gage R&R analysis. The results indicate that your measurement system is responsible for 40% of the process variance (GRR%). You look up the guidelines on the internet and this is what you see:
This is the second in a four-part series on Gage R&R. The first blog explained what a Gage R&R study is. This blog examines the relationship between the Gage R&R results and the process variation and answers the question:
Is the measurement system capable of telling the difference between the parts or samples taken the process?
This is the first of a four-part blog on gage R&R. It answers this basic question:
What is a Gage R&R study?
If you google this question, you will get several answers including this one from the www.isixsigma.com dictionary:
“Gage R&R, which stands for gage repeatability and reproducibility, is a statistical tool that measures the amount of variation in the measurement system arising from the measurement device and the people taking the measurement.”