How to “Expand” Your Gage Studies

Minitab Blog Editor 08 May, 2013

As we said in yesterday’s post, it’s been exciting for Minitab to be a supporter of the ASQ World Conference on Quality and Improvement taking place this week in Indianapolis. There have been many great sessions and an abundance of case studies shared that highlight how quality teams worldwide are improving the performance of their businesses.

One session that generated a lot of interest from the conference participants was conducted by Minitab trainers Lou Johnson, Daniel Griffith and Jim Colton.

Presenting Expanded Gage R&R Studies at the ASQ WQCI Event

Their presentation, Sampling Plan for Expanded Gage R&R Studies, covered Gage R&R studies and how the Gage R&R tools in Minitab can help you account for all of the important factors in your study and overcome some of the roadblocks that traditionally make these types of studies challenging.

What is a Gage R&R Study?

Let’s take a step back … What can Gage R&R studies tell you? Well, for starters, Gage studies can tell you if your measurement system is producing data you can trust. After all, if you can’t trust your measurement system, then you can’t trust the data that it produces. Specifically, Gage R&R studies can also help you understand if your measurement tools are consistent, if your measurement system is sensitive enough, and if the people taking the measurements are consistent.

Expanded Gage R&R Tools in Minitab

Traditionally, Gage R&R studies focus on just two factors: parts and operators. But what if you want to take your measurement systems analysis beyond just parts and operators and include other factors that also influence your measurement system?

If you don’t include these factors, you’ll never know how much they affect measurement variability, and your measurement system may look better or worse than it really is. Expanded Gage R&R in Minitab lets you include up to eight additional factors, so you can investigate the impact of all the factors that may affect your measurement system.

For example, say that testers working on a hectic production floor are concerned that shifts in production speed are affecting their ability to measure. By adding line speed as a factor to their gage study, they are able to see that changes in line speed influence their measurements even more than they suspected.

Expanded Gage R&R in Minitab

You can find Expanded Gage R&R in Minitab by navigating to Stat > Quality Tools > Gage Study > Gage R&R (Expanded). The dialog window for this tool may look a little different than the traditional Gage R&R dialog, but the rules remain the same: you still need to enter in columns for Part, Operator, and Measurements:

Expanded Gage R&R

For more on performing an Expanded Gage R&R study in Minitab, check out these additional resources:

Unbalanced Designs and Gage R&R (Expanded)

Accuracy vs. Precision: What’s the Difference?

What’s your experience in performing Gage studies?

If you attended ASQ World, what kinds of take-aways are you headed back to work with? Please share in the comments below.