% Tolerance - Type 1 study on the gages, then a gage R&R (ANOVA)

[nvpeter]

Hello, I am new to the whole MSA process. My current project is to do a type 1 study on the gages, then a gage R&R (ANOVA) on the process that uses the measurement tool. After this, the customer would like me to come up with a specification on what the gage can be used for. I would have thought this would pertain to the resolution of the gage but the customer would like the %tolerance to be incorporated in this as well. Has anyone have any experience with this?

 

[Miner]

After this, the customer would like me to come up with a specification on what the gage can be used for. I would have thought this would pertain to the resolution of the gage but the customer would like the %tolerance to be incorporated in this as well. Has anyone have any experience with this?

The customer is just asking you to take the Study Variation and divide by the maximum acceptable %Tolerance to determine the tightest tolerance for which you may use the gage.

 

[nvpeter]

Sorry if I am misinterpreting, so lets say if :

tolerance:+/- 0.005"
Study Var: .0111
%Study Var: 19.11%
%Tolerance: 19.99%

the risk of the measurement system is risking making an incorrect decision form the tolerance is 19.99% and so the tightest tolerance for the system should be +/-0.002 more than the usual (.01 * .1999 =~0.002). Or is this entirely wrong.

 

[Miner]

%Tolerance: 19.99% is interpreted as meaning the measurement variation consumes ~20% of the tolerance. Regarding the tightest tolerance that you can use this gage to measure, it depends on what threshold you set for an acceptable %Tolerance. Are you using 10% as the max acceptable? Is 20% acceptable, or 30%? For the sake of the example, let's say that 15% is the maximum acceptable %Tolerance. Divide the study variation by the max acceptable %Tolerance (15% or 0.15) to get the tightest tolerance the gage can measure.

 

[nvpeter]

I am using 20% as the max acceptable. Thanks for making this clear to me!