G
Geese
In the GRR report, TV (total variation) is calculated using the calculated GRR and PV. However, in the analysis section of the MSA 3rd edition pg. 116, it states that the TV may also be calculated using process variation / 6.00 if the process variation is known.
The reason I'm presenting this is that we have 2 separate report forms that calculate TV using these 2 different methods, only they call TV Tol in the 2nd report. And in the 2nd report, Tol is calculated using upperlimit - lowerlimit / 6.00 instead of process variation / 6.00. Is process variation = upperlimit - lowerlimit?
To verify the authenticity of this method or our report rather, I need to know what the upperlimit and lowerlimit numbers refer to. Do they refer to the tolerance of the actual part being measured, or are they a calculated number. Our report thinks they are the actual tolerances of the part and puts them in as such, but I want to make sure that is what they actually are, but process variation does not sound like it would be the actual tolerance on a part.
The reason I'm presenting this is that we have 2 separate report forms that calculate TV using these 2 different methods, only they call TV Tol in the 2nd report. And in the 2nd report, Tol is calculated using upperlimit - lowerlimit / 6.00 instead of process variation / 6.00. Is process variation = upperlimit - lowerlimit?
To verify the authenticity of this method or our report rather, I need to know what the upperlimit and lowerlimit numbers refer to. Do they refer to the tolerance of the actual part being measured, or are they a calculated number. Our report thinks they are the actual tolerances of the part and puts them in as such, but I want to make sure that is what they actually are, but process variation does not sound like it would be the actual tolerance on a part.
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