Choosing not to calibrate (IATF 16949)

benmg

Registered
Hi all, I could do with an idea if this would be acceptable or not.

I am looking at calibration with a sensible eye after i have inherited a bloated and unrealistic system.
One massive pain is the fitting / trimming aids we use, there are hundreds of them, completely impossible to calibrate and get lost and moved daily.

We manufacture car interior parts to a known master, and set of standards, however sometimes we use a mating panel to double check how it would look when finished.
(What we can let go, how a seam might look when pressed against another part etc.)

I hold that these are not gauges, they cannot be calibrated (even verified really), they are not used to check a part to any standard or customer requirement.
Purely as an assistance to manufacturing.

My plan is as such:
-Keep a list of the parts and what they are for.
-Include them in work instruction as the aids they are meant to be.
-Individually label them as aids and the review them before each use for damage (they cannot wear only break).
-Change our process to clearly identify these items as aids and state that we do not calibrate them.

This would make my life so much easier and less risk.
Is there anything obvious that i have missed that would bring issue under audit.
 

AndyN

Moved On
Calibration is appropriate, but verification is. Verification can include periodic checks to ensure the condition of mating surfaces, features etc such that the mating part is correctly evaluated.
 

Ninja

Looking for Reality
Trusted Information Resource
Calibration is not appropriate, but verification is.
I think Andy missed a "not"...

The question would be "How do you know your part is good?"
When you say
Purely as an assistance to manufacturing.
you're already halfway there...
The other half is to consider "What goes wrong if the tool is bent/damaged/off-size/etc." and "Where in the process will that be caught?"

I used a granite surface plate and shims to set a gap in processing, and adjusted that gap by means of micrometers...none were calibrated.
The gage measuring the resulting product was calibrated, and that is what mattered.
Taking this approach (and not wanting to explain it to every auditor who walked by), I put the rationale right in the procedure document as notes.
Note 1: blade micrometers do not require calibration because A
Note 2: Surface plates used for setting gaps do not require calibration because B.
etc...
Once those notes were in place, I never had another question or issue about it.
 
T

TKaplan

I think the important point here is that these items are, as noted in the initial message "not used to check a part to any standard or customer requirement". I'm assuming there are other gauges and measurement equipment that performs that function.
In my minds eye, what we have here is a dress makers dummy; something to set a part to and look for flaws. If the part is not being modified or measured in any fashion through the use of this device, but is only being visually checked, then I wouldn't think that these items would need to be listed as calibrated equipment.

Validation of the condition of these items would be useful yes, but only if the damages or possible flaws to the items would result in a change or any type of acceptance / rejection of the product being analysed. From the description, it doesn't sound like that would be the case.
I have seen plenty of little gadgets and gizmos that make the production process better, faster, and more efficient. Not all of them are used as measurement tools against a products CTQ, and are therefore not calibrated equipment. In my humble opinion, if this is the case here, then it is as Benmg said.....they are 'aids'.

I agree with the advice already given...list these items in the OWI's, SOP's, and Visual Standards as "Visual Aids unrelated to validation of CTQ", and be done with it.
 

benmg

Registered
Thank you all for the comments, i have now started reducing our "gauge" list, in some areas this is by as much as 75%.
We have our next CB visit in March, i feel confident that this will be acceptable.
 

Ninja

Looking for Reality
Trusted Information Resource
It's all about whether it is a "tool" or a "gage"...
Or to say the same thing another way...are you getting data from it? Do you make decisions based on that data?
 
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