Defining Process Changes and Customer Notification Requirements

[GoKats78]

Help determining "Process Changes" and "Customer Notification"

We are at loggerheads as to what exactly constitutes a "Process Change" and "Customer Notification" requirements.

Here is the scenario:
We are a tube maker supplying tube to the automotive industry. We have an approved PPAP for a product. Our PPAP was submitted with a 0.250 wall. We are looking to "down-gauge" to a 0.242 wall.
Both of the walls are within the customer specification.

The team is split:
- This is a process change therefore requires notification.
- We are still within specification therefore this is not a change and no notification is required.

Opinions Please!

 

[SteelMaiden]

Our PPAP was submitted with a 0.250 wall. We are looking to "down-gauge" to a 0.242 wall.
Both of the walls are within the customer specification.

The team is split:
- This is a process change therefore requires notification.
- We are still within specification therefore this is not a change and no notification is required.

Opinions Please!

Greetings GoKats,

We might not have enough info to truely give you a right answer, but heck, the lack of information has never stopped me from opening my mouth!

First issue (as I see it):
You say you want to reduce the gauge by .008 inches and it is still within spec. That is fine, but will this change your capability indices? I've never worked with tube, but in bar product an 8 thou drop in dimension was significant. Is this going to put you near the spec limits? If so, it is very likely to make a big change in capability. Therefore, you need to run some studies on capability, no?

Second issue (again from my viewpoint)
What is the customer doing with the tubing? If they are fitting something into it, or over it, and all of a sudden they end up with a hole that is .016" larger in diameter (or a tube that is .016" smaller OD) will it cause a problem for them because they are expecting a .250" gauge tube wall?

I would be concerned mostly with the capability indices, as automotive customers will probably expect you to repoert those numbers with some frequency and will wonder why the shift.

 

[GoKats78]

Our product is made to an OD specification - the change in wall thickness will not effect the finished product in from, fit or function.
The capability indices are not affected by the change.
The end use will not be effected by the change in gauge either.
The 0.250 wall is near the top specification, the 0.242 wall is closer to the minimum - but both are within spec.
Hence - the dilemma!

 

[SteelMaiden]

Kats, if you can change the gauge and keep your capability indices at or above your current approved status, you should be fine if there is no effect in form, fit or function? (just remember that this "advice" comes from someone no longer in the automotive world and should be weighed carefully before taking it!)

 

[p_tww]

We are at loggerheads as to what exactly constitutes a "Process Change" and "Customer Notification" requirements.

Here is the scenario:
We are a tube maker supplying tube to the automotive industry. We have an approved PPAP for a product. Our PPAP was submitted with a 0.250 wall. We are looking to "down-gauge" to a 0.242 wall.
Both of the walls are within the customer specification.

The team is split:
- This is a process change therefore requires notification.
- We are still within specification therefore this is not a change and no notification is required.

Opinions Please!

Not sure whether you had PPAP manual (3rd edition), it difined various situations for customer notification/PPAP submission.

 

[Randy Stewart]

GoKats78,
A word of caution. With what has happened in the auto industry lately (gas tanks exploding, tires, etc.) I would be cautious not to notify the customer of the changes. Reason being, passing the buck to avoid a lawsuit.
That would be my only reason for not just going ahead and doing it. It would probably take you 3 months to get the okay and then they would ask for a price decrease because the part has less material, or something.

Proceed with caution.

 

[howste]

To me it's pretty cut and dried, based on my past experience and the TS 16949 requirements. If you're making a conscious decision to change from what was approved in the PPAP, you need to notify the customer. I've been an automotive customer receiving tubes (suspension struts), and I would have been very concerned if a supplier changed the target wall thickness without notifying me. Here's a quote from TS 16949 7.1.4:

The effects of any change, including those changes caused by any supplier, shall be assessed, and verification and validation activities shall be defined, to ensure compliance with customer requirements. Changes shall be validated before implementation. For proprietary designs, impact on form, fit and function (including performance and/or durability) shall be reviewed with the customer so that all effects can be properly evaluated.

It sounds like you have evaluated the impact on form, fit and function, but the requirement says the impact shall be reviewed with the customer.

 

[p_tww]

To me it's pretty cut and dried, based on my past experience and the TS 16949 requirements. If you're making a conscious decision to change from what was approved in the PPAP, you need to notify the customer. I've been an automotive customer receiving tubes (suspension struts), and I would have been very concerned if a supplier changed the target wall thickness without notifying me. Here's a quote from TS 16949 7.1.4:

It sounds like you have evaluated the impact on form, fit and function, but the requirement says the impact shall be reviewed with the customer.

Impact review with customer was only for proprietary design.

 

[richard b. thomas]

I agree with p_tww, it has been my experience in the automotive industry that changes to specification require supplier notification to the customer. The customer will most likely require capability data to ensure that you can produce the component within the new specification over time and they will determine whether you will have to re-submit PPAP.
It is in your organizations best interest to notify the customer prior to implementing changes. Sub-clause 7.1.4 Change control addresses what your organization is proposing to do.

Good Luck

 

[Bill Ryan - 2007]

Don't know if this will have any bearing on your decision or not, GoKats78 .

We are a die caster and, as such, we, typically, make cores (for example) at the high end of the specification. If, for some reason, they don't wear at the rate we expect, we may turn them down to nominal (or close to). Will I notify my customer? NO WAY!!!!! Granted, we don't normally have "as cast" holes as KPCs so we don't normally collect variable data on them.

I agree with Steel's mentioning of capability indices and making sure that they haven't changed much (but if you're changing from a Cpk of 5.0 to 2.0 you're customer won't even be aware of it, will they?).

I think I could argue that it isn't a change to the process, merely a change to a target. I'm not saying you shouldn't let your customer know, and, in fact, I'm a strong proponent of letting my customers know what we're doing - within reason. If you're truly sure it doesn't affect fit/function/reliability, I don't see any value in bringing the customer on board (in fact it would probably add cost).

I agree fully with Stew's word of caution. The point I'm trying to make is that you have a specification from your customer to hold an OD within .238/.252" diameter (just for agument). The customer's requirements have not changed . If you are capable, anywhere within that specification, you are good to go, whether you're mean has changed from the PPAP submission or not.

Now that I've dug myself a hole (and yes I'm waiting for the barrage), let me say that my "true answer" would be "It depends". Lots of help, huh?

BTW, Welcome to the Cove

Bill