Engineering Change Validation - 4.2.4.3

[Douglas E. Purdy]

I must be brain dead after going through our second follow-up audit last week. I was reading our procedures concerning this requirement and for the life of me I can not make sense of the 4.12 and 4.16 reference in this requirement.

"The supplier shall verify that changes are properly validated. See 4.12, 4.16 and PPAP."

Thanks for the enlightenment!

 

[Marc]

Well, let me see now. Let's say an 8-D invesitgation reveals a root cause which involves an EC. A typical EC system will require you to go back to your APQP plan - that is to your design and development roadmap. Let's say it is a spring which affects the return of a brake shoe on a foundation brake. You make a material change. You look at your map and see that there was a validation test and information was taken on the spring. You know you have to go through your validation test again. But - let's say that the spring is not with a critical characteristic and nothing in any validation testing had anything to do woiith the spring. In this case you have to, as a 'professional' design engineer, make a decision as to whether or not you need a validation test on that spring for any reason. It may be that as you look at the part history the spring was long ago validated and since no problems have come to light eventually the validation requirement for that spring was dropped. As an engineer you have to consider: is the material change sufficient, with consideration of its role, environment, etc., to warrant validation testing either to the original validation requirement(s) or, possibly, to a new 'specification'.

Your engineering change system should guide you in this to some degree.

4.12 .1 Supplemental Verification adds that your customer may decide additional verification tests and/or requirements are necessary above and beyond what you require.

4.16 says you have to keep records of validations.

PPAP - well, as I said above....

Does that help or have I confused the issue?

 

[Douglas E. Purdy]

Marc,

Yes your explanation makes since if you have design (4.4) as part of your system requirements. But should not the design validation be performed prior to a revised PPAP?

If you do not have design (4.4) as part of your system requirements, then is all I am to look for is that the revised enineering specification and/or drawing was approved and part of my PPAP package?

Or is the requirement trying to say that I am to validate how the engineering change affected my PAPP?

To me there is a difference between verification and validation.

[This message has been edited by Douglas E. Purdy (edited 15 March 2001).]

 

[Marc]

Well, it all depends on your overall role. Some companies do not do design but participate or perform certain validations. Most companies have their own validation tests for their design, but not all. What role did you play in the APQP process? Sounds like you neither designed nor participated in any validation. On the other hand you may not do design but assemble an assembly which you do validate.

What I always do is look at the APQP roadmap for that product.

->But should not the design validation be performed prior to
->a revised PPAP?

Well, you're looking at your roadmap and ask yourself what, if anything, will have to be repeated. just like during APQP you essentially make a plan. Do you have to repeat any runoffs? Is there validation testing to do? Etc.

PPAP is just the warrant submission and, depending upon the level required, parts, data, etc. It's done after everything else. Think of PPAP as one big report on what was done during APQP or in response to a product change.

If you are saying a supplier to you did a design change and you don't know what to ask for (you are supposed to be involved) it's a matter of reviewing their roadmap, their proposals and their possible effects on your product. From that you look at both your roadmaps and determine what (which), if any, validation(s) have to be repeated.

->Or is the requirement trying to say that I am to validate
->how the engineering change affected my PAPP?

That as well.

 

[Al Dyer]

Hope this helps,

If there is a change, you need to return to ground zero (contract acceptance) and review all of your documentation (APQP/PPAP). With this review you will discover the items that need to be re-evaluated (validated), changed, and re-submitted.

With this change, the records (evidence) will be updated and added to some type of record retention matrix, or whatever tool you use to monitor records.

ASD...

 

[Marc]

->return to ground zero (contract acceptance) and review all
->of your documentation (APQP/PPAP).

Exactly. Your APQP product / process roadmap.

 

[Douglas E. Purdy]

Thanks for your explanations.

 

[Marc]

->Or is the requirement trying to say that I am to validate
->how the engineering change affected my PAPP?

What I meant is you have to evaluate (rather than validate) whether the supplier's change will affect your product. Whether you have to do any re-validation(s) is determined by that evaluation.