Test Box Validation: Is it required?

If it is not validated, how can you trust the results? If it does not effect the product or it's functionality, what are you testing?

Each module undergoes testing at the manufacture point; there are 11 modules total. This final test is done after full assy before it is sent to market.

So, the question remains - is this a useful test or not? If it is, you owe it to yourself to be able to validate the results. To do otherwise would be like a machinist using a pair of calipers that had never been calibrated. If this is not a useful test, stop wasting resources on it.

I agree completely!!!!!!!

Any test jig, instrument etc, should be 'calibrated' 'checked' 'validated' or whatever you want to call it...this should be done using instruments which are in turn calibrated etc, such that the chain is traceable back to national (and hence international standars).

This is the fundamental premise of all calibration systems.

Alternatively you could just check it against that old stick in the janitors closet..heck that'll do.

Del

To be more specific...Even a simple hand crafted mechanical go-no go gauge should be made to a drawing with dimensions and tolerances which are measured and checked with instruments which are calibrated, and can ultimately be traced to national standards.

Out of interest... a while back I took two plastic rules which were on my desk and checked 'em against eachother there was 3mm difference over the 300mm length !
(I'd noticed a problem in a 1;1 sketch of of a bracket that I was doing) Needless to say I threw one of 'em away, checked them against a steel rule from the factory floor.

Del

If understood correctly you want to know if you really have to enter yes or no on a computer after all the testing has been carried out in any case,

I would imagine that the entry link the inspector to the particular item. If at a later stage the product is found to fail the inspector can be called on to testify that the product left the assembly line in a good condition.

The answer is therefore yes it is necessary.

The answer depends on the nature of the testing the unit does. IF the final test unit assesses functionality only - ie. It tests the analytic unit for the presence or absense of an output, function, or signal then it could be considered self calibrating.

If the unit assesses the utility of the system output then the test unit must be calibrated against an know standard by a reliable method, and possibly by an accredited testing company.

As a gage technician with a high tech company some time ago I was expected to test all the gages in a complex panel that assessed the function of my companies product. As time passed and I learned the true nature of a gage technicians professional responsibilities I came to realize that I was SUPPOSED to be assuring the performance of the test instrument, not just the components thereof.

It turned out that the output of the test panel was in error and had been for a decade or so. New test methods were in developed and a new comprehensive calibration procedure was developed. Our ISO 9000 procedures mandated a product recall that covered several product lines and at least a decade of product. We did in fact get a lot of obsolete and or defective product returned by several customers which caused economic losses for the company. But, more importantly we had lost credibility within the industry.

Even though I did not cause the problem, had been instrumental in finding and helpful in correcting it, I got sacked. Lesson learned. You can cut corners on this one if you want to, but I would highly recommend calibration of the function of any final test instrument given the industry your company works in.

On the other hand. The engineer who fucked up the first instrument panel probably still works at the company I was forced to leave, so who knows, you might get lucky.

All the suggestions made are what I expected, but our team of ME's agree that this is a waste of time and resources. The test-box only cycles the solenoids and a few other valves and some level sensors. It does not test for analytical accuracy of the diagnostics it will perform as an Analytical Instrument.

All the suggestions made are what I expected, but our team of ME's agree that this is a and resources
This is entirely bonkers... If you don't want the answers don't ask us to participate in your 'waste of time'

If it only cycles a few solenoids and valves...then validate it once a year by checking that it 'does exactly what it is specified to do'

It must still have a specification and a design drawing...!!!

Check that the damn thing does what it is supposed to, tick the box and then get on with some thing more important. It's not rocket science.

A slightly irritated

Del

Sirs, Validation is not simply calibration. It entails alot more that the word implies. There are a host of phases and decisions that are made when involved with Pharmaceutical and Medical devices. A test box can be designed and built and some way along the line can be discarded entirely as not fit for purpose.

Validation is not simply calibration.

Indeed it is not.. the word implies checking that the test is valid i.e Performs a useful function.

Quite right..if it is not performing a useful function why are you doing it?
If it is performing a useful function then it should be checked periodically to check this fact!

My personal view is that 'validation' is one of a crop of vague weasel worlds utilised by pencil pushing idiots who have no idea of the real world. Last time I had my ISO9000 audit I had a long discussion (read amusing piss taking argument) with the guy about what exactly validation means... Are you validating to the spec' ? Or are you checking that the spec' is valid ? (it often isn't as the customer often thinks he wants something entirely different to what he needs)

Next time he visited he said.
'I went back to the office and we had a discussion, we couldn't agree an a definition among ourselves.'

Del

Del,

I've read many of your entries on this forum and have come to respect your intelect and scientific and engineering opinions.

Validation, as I see it in the medical field, is where you literally validate with objective evidence that your design outputs (line item by line item) satisfy your design inputs. There should be a document in your design history file (top level and detailed design spec) that clearly id's your design inputs. Your validation and verification activities should address each one of those inputs one by one with objective evidence.

As to your comments on this thread, my comment to you would be to simply not respond to a thread if you feel like it is a bad question or somehow not worthy of your time. Just move on to something else instead of submitting a rude comment. I say this with respect because sometimes I get responses like yours and it just doesn't make sense for you to submit a comment if it is wasting your time.

Vis a vis being rude etc..I have conversed privately with Ronald on this matter (e.g appologised as soon as I posted it)...and maybe my humour is a tad off , doubtless my week long toothache has been a factor . (just had 3 root canals done this morning)

Back to the chase...
I was pulled up by auditors regarding not only performance validation against the spe'c but also spec' validation!!! .... hence some of my other comments.

(Sorry to have been an arse...it's an occupational hazard of trying to be funny too hard on occaision )
Regards
Del

One way round this conundrum is to label the test device "Indication only". That puts it outside the need for a formal validation procedure.

Procedure would be to

1. List all possible faults that the Test-box will check for.

2. Test against known good equipment. Does Test-box indicate "go"? Record results

3. Inject a fault from your list and test. Does Test Box indicate "No-go" Record results

4. Repeat for the rest of possible faults on your list.

5. Repeat for combinations of faults on the list.

Date and sign results. If all results are expected, Validation is complete.

Thank You all so much for your input...Yes, especially "Del the Cat". I know his humor and level of aggravation. You're forgiven Del.

For the rest, I deeply appreciate all the answers and suggestions. You are all PRO's.

Ron Sanchez