Calibrate before equipment gets modified?

[Charles Wathen]

I recently had to change my departments calibration procedure to list the steps we take when equipment gets modified. I found it intresting that our sister company in Ireland wanted to calibrate the equipment first before the modification. I felt that this was not necessary and redundent extra work.

Anyone have any thoughts on this? We are a Medical Device company.

 

[Bubba]

Whenever a calibrated device is going to be modified, it should be calibrated both before and after the modification. This gives the company documented evidence that the device was operating within proper specifications for the entire time that the device was used. Then the calibration after the modification assures that the device is continuing to operate within proper specifications. In other words, the before calibration makes sure it wasn't screwed up before you modified it, and the after calibration makes sure the modification itself didn't screw it up.

We are also a medical device company. The FDA wants you to be able to prove that all product that was manufactured/inspected/released by the use of calibrated equipment meets the specification, whether before or after a modification.

 

[Charles Wathen]

Thanks for your reply. Is this documented anywhere in the FDA docs?

 

[Bubba]

From 21 CFR Part 820.72 (a)

"Each manufacturer shall ensure that all inspection, measuring, and test equipment, including mechanical, automated, or electronic inspection and test equipment, is suitable for its intended purposes and is capable of providing valid results. Each manufacturer shall establish and maintain procedures to ensure that equipment is routinely calibrated, inspected, checked, and maintained. The procedures shall include provisions for handling, preservation, and storage of equipment, so that its accuracy and fitness for use are maintained. These activities shall be documented."

From 21 CFR Part 820.72 (b)

"Calibration procedures shall include specific directions and limits for accuracy and precision. When accuracy and precision limits are not met, there shall be provisions for remedial action to reestablish the limits and evaluate whether there was any adverse effect on the device's quality. These activities shall be documented."

When you make changes to a calibrated device without first ascertaining its current accuracy, you have lost traceability for that instrument clear back to the last time it was calibrated. You are assuming that nothing changed between the time of the last calibration and the modification, but you can't realistically prove it. The same principle applies when calibrated devices are being retired or placed on an inactive status. The device should be calibrated immediately prior to storage or disposal so that traceability extends all of the way to that point. That way if you relied on any measurements that were possibly inaccurate, you know about it and you can evaluate any possible adverse effects on your product. CYA:ca:

 

[Charles Wathen]

OK. My thinking was if an instrument was working fine with no problems on line, and then it was pulled for modifications, it would not require calibration because it was functioning correctly as intended when it was pulled. If the instrument remained on line until it's next calibration due date, it would then be checked by our calibration department again. I'm trying to use some statistics here based on the equipment for my decision. I don't know if this would be an audit observation, as we have not received one (yet).

 

[Bubba]

My thinking was if an instrument was working fine with no problems on line, and then it was pulled for modifications, it would not require calibration because it was functioning correctly as intended when it was pulled. If the instrument remained on line until it's next calibration due date, it would then be checked by our calibration department again.

My question to you would be, how do you know that an instrument is working fine and functioning correctly(with accuracy) unless you calibrate it? If you have a way to show that the instrument is functioning as intended without any calibration, why are you calibrating it?

One purpose of a calibration system is to be able to find problems with accuracy, reliability, precision, etc. that would not necessarily be apparent any other way. When your calibration department pulls the instrument on the proper due date, they are looking for these kind of errors. If they found an error in accuracy, according to the FDA, remedial activity would be required and you would also need to assess any potential adverse effects on product manufactured with that instrument, possibly clear back until the most recent successful calibration.