Im sure this has been discussed but I am not finding much on this discussion. I need to find out if I have to perform Gage R&R on each measuring device used or is it just for each family of devices. I am getting mixed answers from everyone i ask but nobody has any evidence for their opinion. so i wanted to bring the question to the experts.

Im sure this has been discussed but I am not finding much on this discussion. I need to find out if I have to perform Gage R&R on each measuring device used or is it just for each family of devices. I am getting mixed answers from everyone i ask but nobody has any evidence for their opinion. so i wanted to bring the question to the experts.

Welcome to the Cove:D

Keeping in mind that gage studies should be performed on parts and not on standards, there is no problem with using a "family" approach. It stands to reason that one six-inch caliper won't perform differently than another, assuming both have been properly calibrated. You should use gage studies to verify that a general type of device is appropriate for the specific intended application.

I agree, one gage from a family of gages is enough under most situations. Dedicated gages should be done individually though.

Taking what Jim said a bit further, you can perform an MSA on a family of gages provided that they are used for similar measurements on similar parts.

For example, if you have ten 0-1" micrometers that are used to measure the diameter of a family of shafts made on the same equipment to the same tolerance, you could group these into a family. This is based on the similarity of gage, features, process variation and tolerance.

On the other hand, if these gages are used to measure different features on different parts made on different machines, you cannot logically group these into a family. Different features, different process variation and different tolerances. The gages could be grouped as a family around each of the different features, but the gage suitability will probably vary from feature to feature.

Perform the R & Rs on families of gauges shown in the Control Plans and not families of parts.

A family of gauges would be up to your company unless you have a Customer specific like, as an example, Ford. They deem a family of gauges as being the same type and maker of a gauge. If you have seven 0 - 1 inch micrometers with 2 of them made by 1 company and the remaining 5 from another company, you have 2 families.

All gauges purchased should tend to reduce the number of families so make sure that if you like Mitutoyo micrometers, you purchase all of the same maker.

Thanks for the responses. This has been quite helpful.:thanx:

I'd like to take this question one step further.

What is the frequency in which we need to perform R&R studies on these devices? Is it defined in MSA? By Ford?

I'd like to take this question one step further.

What is the frequency in which we need to perform R&R studies on these devices? Is it defined in MSA? By Ford?

I'm pretty sure that you should be asking Kenneth (http://en.wikipedia.org/wiki/What's_the_Frequency,_Kenneth%3F) about the frequency. :D

Seriously though, unless there are CSRs involved there's no reason to repeat a GR&R unless something significant has changed, such as new operators. Assuming the original study was correctly performed and gages are properly maintained and calibrated, I can't think of a good reason to repeat a gage study.

Although I agree with the replies regarding gauge families and no need to repeat gauge studies, I am finding it hard to convince people in our organisation.
Can anyone point me to where it's documented that not every gauge needs an MSA and they only need one MSA unless something changes.

Thanks in advance

Brian

The Customer specifics give the answer, in your case the requirement is to establish the baseline - once, and then when called upon be able to repeate.
Retention of masters can help as the parts received today tend to be from capable processes which does not help with the signal to noise ration.

Hello everyone!
I have several questions. I am in a new position with the responsibility of PPAP packages. This is the first time a customer has requested a PPAP and I am diving in head first not knowing the depth of what I'm diving into. :mg: The customer does not specify ANY requirements for individual pieces of the PPAP so I am assuming that our company has discretion as to how to perform the tasks.
My task at hand is Gage R&R (MSA). Inspection of several features is done by using gage blocks and plug gages. If the tolerance is +.002"/-.000" and our plug gages are in increments of .0005", is this acceptable since it cannot follow the rule of 10? Also, because an actual measurment isn't being taken, only go/no go determinations, can a gage R&R be done? Should a more labor intensive measurment be taken to determine more a more precise number?
The process uses 2 different lathes and a milling center to machine the entire part. Does a Gage R&R need to be done on each family of gages on EACH machine or can I do a single family for the entire part?
Any guidance would be appreciated. ;)