what is evaluated on the Gage R & R report to be considered acceptable? percent total variance or percent tolerance? is it ok for the percent total variance to be at 91% ? also, regarding (NDC): Is it the percent tolerance column or the percent total variance column that should be 5 or greater?
It is my understanding that your percentage should be under 10%. I have found when I have the asterisk next to a measurement, that means there is a significant difference in the range of measurements and that throws off your repeatability, so making your results worse. Some things that fixed my issue was to ensure that I typed my values in correctly- reversing a number or a wrong number typed makes it way out. Other things to keep in mind is ensuring the auditors are following the same exact procedure; as you can see, one operator getting 1.97 and another that gets 1.99 may only be a difference of .02, but that is using more of your tolerance range, so less repeatability. You may need to have your auditors repeat the measurements of that specific part and if it remains the same, may need to look that your process for measuring needs to be worked on.
Here is an example of one of ours- keep in mind that ours is for a CMM, so we have removed most of the human error that caliper or micrometers would have. The difference on a CMM is a matter of the auditor fixturing the part.
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