PPAP - Complaint from a Tier One customer concerning Product Dimension

[tongxiaozhi]

Dear Quality Gurus:

I received a complaint from our customer(Tier one) concerning product dimension. Actually, the issue was found by OEM during an audit of our customer. I checked that the measurement is comparable with PPAP we submitted 4 years ago and our customer approved the PPAP.

The customer required us to modify the mould to correct this issue, for us , it will be very costly to modify the mould. Does our customer also have some responsibility for the issue? (Because PPAP was approved and the part has been used for 4 years)

Thanks for your reply in advance.

 

[Marc]

Either your product is within dimensional (or other such as "grain" or color) requirements or it isn't. If they haven't changed the spec (contract revision or waiver or deviation agreement), and you are producing to spec, there is no issue.

However - If you are using a mold/die and it has worn so it will not produce in specification parts (we all know molds/dies wear is reality), you should have caught it in-house prior to shipping and discussed it with your customer to resolve the issue. It is not an issue of whether the part is "comparable" - It is whether the part is within the specification(s). It either is, or it isn't.

I have seen this come up many times over the years. Molds/dies wear. In your original contract, you should have, if you didn't, specified who is responsible for mold repairs including wear issues. If you didn't, good luck. Your company accepted a contract where no one is assigned responsibility for mold/die wear/repair. This only leads to p!ssing matches when wear or other similar "happens".

Even if the part hasn't been produced for 4 years, or 10 years for that matter, the requirement is that the part be made to the original specifications unless you get a contract change, a deviation or waiver.

 

[Marc]

Oh, and another thought. Often PPAP in metal flowing/stamping, and in injection molding to a lesser degree, is on specific presses or injection molding machines. Often a die will work in one press but not be able to produce in-spec parts on another. This is especially problematic when you have a progressive ("prog-die") scenario with multiple dies and sequential presses. Every press has it's own characteristics so check your original PPAP and see if that is an aspect that was recorded.

 

[Golfman25]

Dear Quality Gurus:

I received a complaint from our customer(Tier one) concerning product dimension. Actually, the issue was found by OEM during an audit of our customer. I checked that the measurement is comparable with PPAP we submitted 4 years ago and our customer approved the PPAP.

The customer required us to modify the mould to correct this issue, for us , it will be very costly to modify the mould. Does our customer also have some responsibility for the issue? (Because PPAP was approved and the part has been used for 4 years)

Thanks for your reply in advance.

Are the ppap parts the same as the current parts? Is this a measurement issue? We frequently encounter measurement issues - you can draw it, but you can't measure it. It becomes a cluster because customer's design and quality don't talk. If the parts are still the same, and work fine, then it is a waste to "fix" the mold. Bring it in with a pencil. Good luck.

 

[Golfman25]

Oh, and another thought. Often PPAP in metal flowing/stamping, and in injection molding to a lesser degree, is on specific presses or injection molding machines. Often a die will work in one press but not be able to produce in-spec parts on another. This is especially problematic when you have a progressive ("prog-die") scenario with multiple dies and sequential presses. Every press has it's own characteristics so check your original PPAP and see if that is an aspect that was recorded.

Actually I would argue that the reverse is true. Stamping is tooling dominant so the press has less of an effect (assuming it is well maintained and not some piece of junk). Molding is much more reliant on machine parameters - speeds, pressures, heats, etc.

 

[tongxiaozhi]

Either your product is within dimensional (or other such as "grain" or color) requirements or it isn't. If they haven't changed the spec (contract revision or waiver or deviation agreement), and you are producing to spec, there is no issue.

However - If you are using a mold/die and it has worn so it will not produce in specification parts (we all know molds/dies wear is reality), you should have caught it in-house prior to shipping and discussed it with your customer to resolve the issue. It is not an issue of whether the part is "comparable" - It is whether the part is within the specification(s). It either is, or it isn't.

I have seen this come up many times over the years. Molds/dies wear. In your original contract, you should have, if you didn't, specified who is responsible for mold repairs including wear issues. If you didn't, good luck. Your company accepted a contract where no one is assigned responsibility for mold/die wear/repair. This only leads to p!ssing matches when wear or other similar "happens".

Even if the part hasn't been produced for 4 years, or 10 years for that matter, the requirement is that the part be made to the original specifications unless you get a contract change, a deviation or waiver.

Thanks for your answer. Actually, we were aware that the dimension was outside specificaiton during PPAP submission and it seems that our customer didn't verify it very carefully and just approved the PPAP. 4 years later, the issue was found by OEM.

For the mould modification, I checked all our contract with the customer that the responsiblity of mould modification is not defined in the contract, I am in the injection moulding industry and I think it is difficult to define the responsiblity. Have you ever seen a contract which defines clearly the reponsiblity of mould modification?

 

[Golfman25]

Thanks for your answer. Actually, we were aware that the dimension was outside specificaiton during PPAP submission and it seems that our customer didn't verify it very carefully and just approved the PPAP. 4 years later, the issue was found by OEM.

For the mould modification, I checked all our contract with the customer that the responsiblity of mould modification is not defined in the contract, I am in the injection moulding industry and I think it is difficult to define the responsiblity. Have you ever seen a contract which defines clearly the reponsiblity of mould modification?

If you where aware of it being out of specification, did you disclose it? If it was out shown as no good on your dimensional inspection report at least you have some argument to discuss a deviation. You also have a exception box on the PSW.

As far as who is responsible for mold modifications -- if it is not addressed in the contract (very likely), then industry practice is that the customer would be responsible for wear and tear maintenance items. However, in your circumstance, the mold never made "good" parts. Then it is probably your responsibility to modify the mold to make the part. If it has been "out" for four years, doesn't seem like a critical issue to me. But good luck.

 

[Mike S.]

I am not in automotive, but.....

If you did not clearly disclose the OOT part to the customer in the beginning, and get acceptance that the OOT value was okay with the customer, then you set yourself up for a nightmare. Just reporting a OOT value in a report is not adequate disclosure.

JMO

 

[Marc]

Actually I would argue that the reverse is true. Stamping is tooling dominant so the press has less of an effect (assuming it is well maintained and not some piece of junk). Molding is much more reliant on machine parameters - speeds, pressures, heats, etc.

Yeah - I've worked in both.

Try using a die in a 20 ton press where it was first run in a 10 ton press, as an example. I have seen many dies which produced good parts in press "A" but would mainly produce scrap in press "B". I mainly saw this in situations where a couple of years have passed since the part was run, but I have also gone through the "three stooges" routine with a new die which would run great in on one press but not in another. I say "three stooges" because all of us were saying essentially what you were saying - It's a die and should run in an similar press of similar tonnage but simply didn't, all the while a die maker, a couple of engineers and I were scratching our heads spending hours "testing" trying to figure out why. We never did figure it out on that job. We eventually just made sure the die was always scheduled to run in the press which it "worked" in.

Even had a weird situation where we had a Michigan die maker who made a die for us. We did a run-off in their shop and got excellent parts. Got back to Ohio and our presses did a good job of making scrap. Back to the die maker - Great parts. Back to Ohio, more scrap.

Presses *can* have a bigger effect than some people think. Even moving a press to a different place in a plant can sometimes change it significantly. Of course, the biggest issue is the complexity of the die and the material.

As to injection molding - Rarely had issues with different machines, but did few times. That was some years back when two shot moulding was coming into prominence.

 

[Bruser]

Not to muddy the waters.... For all the Tier 1 customers that I have worked with we were required to provide annual revalidation (Dimensional, material cert and PSW) and submit to the Tier 1. If you have an ongoing history of resubmission with approval they have ownership in the issue. If not you only have a small piece of ground to stand on "But you said it was OK".
Obviously the "Fit, Form, Function" is acceptable otherwise this would have blown up earlier. Using that logic I would approach the customer about a print change. Just my $.02