Handling Calibration Postponement - just a note/deviation report/others?

Quality Priest

Inactive Registered Visitor
#1
I'm looking for some feedback on how you guys would/ have handled Calibration Postponement.

We have a sampling machine for thermal conductivity, which was due to be calibrated in week 5 (Very expensive involving the a company representative coming over from Europe to the UK), but as we were purchasing a second model it was decided to postponement, the calibration until the new model arrived when we would have both done at the same time.

The calibration had therefore been booked in for week 16, however due to delays with the manufacturing of the new model the calibration will not be conducted until week 25.

We have an external surveillance audit coming up in the next couple of week. I don’t think this will prove to be a problem for us as we have a planned calibration date and the machine is checked on a weekly basis against reference samples prior to use.
What i am looking for is how you would handle this;
Just a note in the calibration file or
Formal document (Deviation) signed off by the Quality Manager or
Some other way?

:thanks: in advance
 
D

Dale D. Barnes

Guest
#2
Re: Calibration Postponement

I have a folder that is labeled "Calibration Extensions". When the need arises for a calibration to be extended I send the Quality Manager an E-mail describing the situation and asking for approval. He/She then replies with the approval and I save that in the file. I had this same issue when trying to get all the CMM's onto one schedule. I showed that it was checked with a certified sphere and all the masters were still within calibration. The auditor was fine with the situation. I also re-label the item with a yellow sticker that states calibration extension. No need to hide anything the luck of the auditor is to choose the one item out of a thousand that isn't done correctly. :D

Dale
 

Jeff Frost

Inactive Registered Visitor
#3
Extension of calibration due date is something that can be done if your calibration data suggests that it will not be detrimental to product quality. Analyze your data to determine if you can justify a temporary extension of calibration due date as you proposed and be ready to explain the extension to your surveillance auditor.

My recommendation would be to create a written extension memo for the devices stating the justification for the temporary extension of the interval with the data analysis attached to it. Have Calibration Engineer (if you have one), Quality Manager and Production Manager sign off on the extension. This documentation package can serve as objective evidence that Top Management is aware of this extension and are in agreement.

If your review of data suggests that it will affect product quality then you cannot extended the due date then have the calibration as scheduled. Also be mindful of customer, regulatory or statutory requirements which may govern calibration activities within you facility. You may be required to obtain a waver from customer or the government on extending the calibration due date.
 

Boscoeee

Inactive Registered Visitor
#4
I'm looking for some feedback on how you guys would/ have handled Calibration Postponement.

We have a sampling machine for thermal conductivity, which was due to be calibrated in week 5 (Very expensive involving the a company representative coming over from Europe to the UK), but as we were purchasing a second model it was decided to postponement, the calibration until the new model arrived when we would have both done at the same time.

The calibration had therefore been booked in for week 16, however due to delays with the manufacturing of the new model the calibration will not be conducted until week 25.

We have an external surveillance audit coming up in the next couple of week. I don’t think this will prove to be a problem for us as we have a planned calibration date and the machine is checked on a weekly basis against reference samples prior to use.
What i am looking for is how you would handle this;
Just a note in the calibration file or
Formal document (Deviation) signed off by the Quality Manager or
Some other way?

:thanks: in advance
My first question is what is the normal calibration interval? Second is what are the risk with extending the calibration cycle?

Additionally, your calibration procedure or work instructions should dictate the process for handling calibration extensions and who approves the extension. If you have the process in place for this analysis and make a business decision to extend the calibration cycle you are good to go.
 

Jerry Eldred

Forum Moderator
Super Moderator
#5
Before getting into my reply -- REGARDING THE PREVIOUS REPLY FROM BOSCOEEE - Although I am now in New Hampshire, I lived in Leander TX for 7 years (worked for Motorola/Freescale) and love Lago Vista. Feel free to send me a private message about the area (love Lake Travis, and hope to get back some day - maybe for retirement). Anyway, back on topic....

You have all covered it so well that my response is more of the same.

Since the Cal Interval is a defined length of time between which statistically a unit can be expected to perform within its specs, a cal interval extension should be based on the same. My present method for extensions:

For my customer- no extensions (a prudent method). I have no argument with it.

For my instruments- There is a defined limit as a portion of the normal interval, and must be supported with in-tolerance history.

My Opinion- Minimum practice for anything that involves product quality must be some legitimate level of statistical evidence that during the period of the extension the instrument can be expected to perform within its tolerance to an acceptable confidence. If you have some history, you could plot drift per time over multiple intervals and develop a prediction curve as to max interval (vastly oversimplified).

You also mentioned a check standard. If your check standard is well characterized and has enough stable history, it may well provide the data you need to justify the extension.
 

AndyN

A problem shared...
Staff member
Super Moderator
#6
My first question is what is the normal calibration interval? Second is what are the risk with extending the calibration cycle?

Additionally, your calibration procedure or work instructions should dictate the process for handling calibration extensions and who approves the extension. If you have the process in place for this analysis and make a business decision to extend the calibration cycle you are good to go.
Nice answer, thanks.

To emphasize the point - you've gotta have something in your calibration management system which helps you to identify how to handle and authorize an extension to the recall date.

Many folks never write this kind of 'wiggle room' into their cal. systems. It's perfectly legit. to do so and you should exercise it when applicable to buy some time etc.

Some proprietary cal. databases have it, if not write a small part of your procedure to say how it's done, create a form and file it! Get it out when you get audited, in cases where you need to show you're in control!
 

Quality Priest

Inactive Registered Visitor
#7
Well thanks all round guys it been helpful :agree1:
Calibration Procedure now updated to handle extensions to calibration periods.
Request and justification for calibration extension document now created.
Just working out maximum period of extension for various items
 

curryassassin

Inactive Registered Visitor
#8
Maybe, one last point. What does your deviations procedure say? Ours says if anything is contrary to procedure, then it is a deviation. We also write tolerances into our calibration schedules, e.g. calibrate monthly +/- 1 week. So if the calibration is performed late, then it is a deviation. Finally, how do you track the issue if it is not recorded as a deviation? You may find that calibration throughout the organisation is frequently performed late, so then you have an opportunity for preventive action.
 
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