Guidelines to determine which equipment to do MSA on

[Urias]

I'm working on the standardization of the MSA procedures in my company and I was asked to set guidelines for determining which measurement equipments should have MSA.
The problem is that AIAG says "to every measurement system", as I understand, and that is too much for us.
1. Something that I don't see specified in the AIAG manual is if the MSA applies only to instruments measuring product characteristics or measuring any product or process characteristics. What is correct?
2. We have instruments that measure in several different operating ranges (e.g. 80g, 200, 500g, 1Kg, 2Kg, 3Kg). Do we need to apply MSA for each range?
3. We have inline equipments where we cannot get repetitions. Need MSA? In the last TS audit, one of the auditors request us an MSA for an inline equipment for measuring water resistivity meter. How can we perform GRR on this?

Regards

 

[Jen Kirley]

Re: Guidelines to determine what need to have MSA

Welcome to The Cove!

I would start with the gages that are used for acceptance inspections and/or testing. I am not sure about the water resistivity meter.

Any other input for our new poster Urias?

 

[Ghoraba]

Re: Guidelines to determine what need to have MSA



That's true that ISO/TS 16949:2002 Standard requires implementation of MSA for each type of measuring and test equiepment system in clause 7.6.1, but for a real world of application you should go through MSA guide as recommended by the standard, you'll find clear explaintions of how to apply MSA and what to do in some cases like you have i.e automed on-line gauging, and scales, etc.

I also sugguest that you contact your OEM customers and ask them for agreement on the measurement strategy for complex or high risk measurements that you may have in your factory and document it in the agreed control plan.

I attached a copy of the concerned page of MSA guide. I highlighted the concerned points. You may have a look and I hope it will answer all your questions.

 

[Allattar]

Re: Guidelines to determine what need to have MSA

I think its a chance for you to go round and for every measurement recorded start asking questions like.

Why do we take this measurement?
What is the result used for?
What is the outcome of the measurement being incorrect?
How do we know we can trust the result as either accurate or precise?

You can expand on this and apply this to any inspection attribute or continous, what is being checked, what is the result, why is it important to us, to our customer.

Then my personal opinion is to start checking the most critical measurement systems first.

The other point, about a measurement device being used to measure different products. Lets say one part is a few mm in length the other a few cm in length. The tool may be very good at measuring the part that is several cm long, but may not be useful at measuring those small items.
It is important to study seperate MSA's on different products that the system is used for.

 

[Urias]

Thanks to all for your support!

So, let's clarify, applying MSA to product characteristics such as acceptance inspection and/or testings will be enough for the TS audit?

 

[n866fandp]

I have been told that you should have a MSA for every type of measurement device mentioned in your controll plan.

 

[Urias]

OK, my next question will be,

if we have in our process cotrol plan that we are controling the temperature by an embeded cotroller (automated on-line measurement), then we need to have MSA of that measurement system. (this adds even more complexity since temperature is a non-replicabe measurment, right?)

Or maybe we should remove that control from the process control plan, since we have not face any temperature related issue so far.

What would be the best action?

 

[n866fandp]

I wouldn't know enough about you operation to say you could remove it from your CP but you may also be able to contact your customer, and ask them for a recomendation. The manufacturer may also have MSA data for that particular gage. However I'm not sure if this would be acceptable for an audit.

 

[Urias]

From my ponit of view, on-line equipments should have only calibration (of course calibration should be performed in-line).
And usually, an less in my company, that kind of equipments are measuring process input characteristics and of course we have other subsecuent mesurements/inspections/tests to detect product quality issues. So, I don't see the need for doing MSA to these equipments.

 

[Ghoraba]

The aim of having a measurement system analysis (MSA) is to know how much does your measurement system - which includes the measuring equipements, and appraisers - contribute the process variability, and that contribution is accepted or not.

So for parameters like temperature, it's better to prepare a REGRESSION analysis to know how much does the temperature affect your measured parts, upon the results, you'll discover whether it strongly affects or it has no significant effect on your product, and you will be able to decide whether it worths to prepare a MSA study for that gage or it's enough to keep it just calibrated.