Control Plan MSA's - Pressure Gages


Involved In Discussions
When section 7.6.1 talks about, "shall apply to measurement systems referenced in the control plan", I'd like some feed back on what others are actually performing MSA's on. Are there any items listed in your control plans that you find no value added in performing a MSA because the output of that process is verified somewhere else?

We are an etching house and there are a number of "measurement systems" in our process that we cannot perform MSA's on such as Pressure gages that are used to check for consistency within each spray tank, thermocouples that report temps to a computer control system, an autotitrator that reports bath concentrations. I mean all these system were put into place so we wouldnt have to be hand measuring these things.

Would it be acceptable to make a note within our Control of Measuring and Monitoring equipment SOP that we perform MSA's on "measuring systems" that have a direct impact on the verification of customer requirements?

Bev D

Heretical Statistician
Super Moderator
Re: Control Plan MSA's

Etching is typically thought of as a "special process". in this case the instrumentation you reference is not used to verify the product it is used to verify - and thus control - the input factors that will determine the conformance of the product to final requirements. A classical MSA is very difficult to perform on these types of devices. Certainly calibration would be required. If you have validated the process (input factor tolerances guarantee output conformance) I would think that would be sufficient.

I understand that some Customers look at this like a black box though, so others will have advice...


Registered Visitor
I agree with you both.

In our company, those gages used for process parameter control are calibrated and it is sufficient to third party auditor.
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