Coordinate Measuring Machine Software Validation Process

cbearden

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Ok.....I'm the end user of a Coordinate Measuring Machine Software (PCDMIS by Brown and Sharp).......My question is about Software/Process validation.
In my mind, I just want to know that the Software is giving me the true results from my measurements........Plus, I want to keep it Simple (K.I.S.S)
So, here is what I want to do.......Take several known standards (Class 1 GageBlocks) and measure them. If the Software tells me that a 1" gageblock checks 1.000005", then I know its giving me correct results.......Software VALIDATED!!!!!!...........
Do you think this would be acceptable to an auditor?

Thanks,
ZeissUser
 

Miner

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Re: Software Validation Process - Coordinate Measuring Machine

I am far from an expert, so others need to chime in here.

What you describe should already be covered by the calibration of the CMM. Most CMM calibrations involve the use of a Ball-Bar that covers the accuracy and volumetric accuracy.

I would be more concerned about the software routines like the distance between features, a bolt circle diameter created from multiple features etc.

However, most commercial CMM software should have been validated by the CMM manufacturer. If your registrar insists that you need it, you should be able to obtain this from the manufacturer.

Most registrars that I have run into on this issue are more concerned with the validation of test software that your company has written, or with highly configurable software to verify that you configured it correctly.

What have others experienced?
 
J

Jcowan - 2010

Re: Software Validation Process - Coordinate Measuring Machine

We ended up buying a NIST traceable Demo Block from Hexagon...
 
B

bradhaz

Re: Software Validation Process - Coordinate Measuring Machine

I work in aerospace and have been up against the same requirement(s).

For validating the software I created a solid model with a selection of different features accommodating all of the ASME Y14.5M-1994 callouts. Then generate a drawing from the model with the GD & T. Program the CMM offline using the model, report against the drawing, and compare the results. Go a step further and include the feature construction points within the model.

Validation using the above approach is dependent upon how the model is brought into CMM. Any translations (Catia, UG, Iges, Sat, etc.) can introduce their own errors. You should be aware of the translation parameters in the authoring system. Translation is a topic in it's own right.

Use the artifact part for dynamically validating the CMM system. It's a good idea anyhow for interim checks between calibrations.

There was an issue some years ago when true position results of a popular measurement software was in error to some degree. I believe the requirement you ask about may be in regards to this matter. If that is the concern then validating the software algorithms without actually measuring anything may be more prudent by not introducing measurement errors.

Our procedures were the result of the AS9100 requirements combined with input from customer representatives along with personal experience. They work well for us and who we serve. Speak with your customers to see what they expect and how they expect it. Good Luck.
 
P

prototyper

Re: Software Validation Process - Coordinate Measuring Machine

I'm not sure where you are coming from with this question but don't forget that a part programme is also software.

PC-dmis software has been through an extensive process of testing and validation to ensure it's algorythms are correct. Your CMM will be calibrated (Usually annually by the manufacturer or a third party calibration company), with traceability to international standards.

What many people assume is that if something is measured on a CMM the results must therefore be correct. Big mistake!!!!

Poor programming can give incorrect results, excessive clamping can distort parts and give errors.

Check and double check your part programmes to ensure datums and sub datums are correct to drawing and reflect the fit and function of the part.

Conduct a Measurement Systems Analysis study. I have seen significant differences between 2 operators running the same part programme due to the way they loaded parts to fixtures and applied clamps.

If the study shows excessive variation from the same parts, different appraisers, etc., you must then investigate the whole measurement system (programme, fixtures, appraisers) to determine where the errors come from and then take corrective action.

Be thorough with this process and you will end up with a robust measurement system and will be able to demonstrate validation of your part programme.
 
D

Dillus

Re: Software Validation Process - Coordinate Measuring Machine

Ok.....I'm the end user of a Coordinate Measuring Machine Software (PCDMIS by Brown and Sharp).......My question is about Software/Process validation.
In my mind, I just want to know that the Software is giving me the true results from my measurements........Plus, I want to keep it Simple (K.I.S.S)
So, here is what I want to do.......Take several known standards (Class 1 GageBlocks) and measure them. If the Software tells me that a 1" gageblock checks 1.000005", then I know its giving me correct results.......Software VALIDATED!!!!!!...........
Do you think this would be acceptable to an auditor?


The answer to this question is based on what standard or requirement the auditor is inspecting to. If it is for Medical Devices then its ISO 13485 section 7.6 refers to ISO 10012, Measurement Management Systems. I recommend you read this if you are in the Medical Device Manufacturing business. This standard is helpful in understanding what is necessary for ensuring your systems are adequate for their intended use and what is expected in the industry. Note this is only a standard, FDA has very specific requirements for Software Validation under:
CFR 820:70
(i) Automated processes. When computers or automated data processing
systems are used as part of production or the quality system, the manufacturer
shall validate computer software for its intended use according to an established protocol. All software
changes shall be validated before approval and issuance. .

and Guidance on Principles of Software Validation.


In my 20 years of experience working with FDA and ISO auditors and various major pharma and device companies , I have yet to see an internally validated CMM apparatus.

Zeiss will provide you a certificate of validation that the Calypso software is developed and tested for the instrument and this may be sufficient, but this depends on your company's products and level of risk, and intended use of the equipment in the process.

If you see an example or have other information please post on this forum trail. :bigwave: :thanks:
 
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