Should we monitor all Significant part Characteristics with SPC?

BACKGROUND
We are being asked to CNC machine low volume castings for an automotive OEM (it's a service part). PPAP was submitted a year and half ago and the PSW signed off and approved. We've made small batches of the part for the last year and a half. Now the Supplier Tech Assistance Rep is asking for SPC monitoring of all SC's.

If so, what is a good sampling strategy to assure the process is stable and under control?

Should we monitor all Significant part Characteristics with SPC?

BACKGROUND
We are being asked to CNC machining a low volume castings for an automotive OEM (it's a service part). PPAP was submitted a year and half ago and the PSW signed off and approved. We've made small batches of the part for the last year and a half. Now the Supplier Tech Assistance Rep is asking for SPC monitoring of all SC's.

If so, what is a good sampling strategy to assure the process is stable and under control?
At this point, I would reply, "Anything you want - Let's draw up a new contract or an addendum to the original to cover payment for this added requirement."

Under NO circumstances would I do it for free at this point if it was NOT a requirement of the original contract. Even then, the clause may have been waived when they accepted previous batches.

At this point, I would reply, "Anything you want - Let's draw up a new contract or an addendum to the original to cover payment for this added requirement."

Under NO circumstances would I do it for free at this point if it was NOT a requirement of the original contract. Even then, the clause may have been waived when they accepted previous batches.

Wes,

I am livid with this new request. Here is the irony in all this. The STA who signed the PPAP was assigned to perform the Q1 audit. It was during theis Q1 audit that she found this concern (see below for the relevant Q1 clause):

""II.1.4
Where Customer has defined an Engineering Specification (ES), or special characteristics that are the responsibility of the sub-supplier, the sub-supplier must show compliance to the ES or special characteristics in its PPAP submission to the Tier one supplier."

Wes,

I am livid with this new request. Here is the irony in all this. The STA who signed the PPAP was assigned to perform the Q1 audit. It was during theis Q1 audit that she found this concern (see below for the relevant Q1 clause):

""II.1.4
Where Customer has defined an Engineering Specification (ES), or special characteristics that are the responsibility of the sub-supplier, the sub-supplier must show compliance to the ES or special characteristics in its PPAP submission to the Tier one supplier."

I can't see a relationship between the cited requirement and doing ongoing statistical analysis. Did you "show compliance" in the original approved PPAP submission? In this case, "show compliance" could be as simple as providing dimensional verification results. I agree with Wes in his contention that if this extra stuff wasn't documented in the original contract, at least by reference, then let the negotiations begin. I also agree with Wes when he suggests that if there was a requirement in the beginning that the supplier didn't enforce prior to this, it may have the effect of nullifying the requirement, especially if they approved what you were doing in the beginning (PPAP approval includes at least tacit approval of everything in it).

I guess the bottom line is we think the action by STA stinks!

That said, you may have to "escalate" the situation above STA to find a reasonable ear. This is an item which will almost always require intervention by "suits."

TS doesn't actually require you to do SPC on special characteristics but you are required to "demonstrate conformity to customer requirements for designation (you say this is already defined), documentation and control of special characteristics." 7.2.1.1

The auditor is correct about the Q1 requirement. You will notice the same requirement in the PPAP manual which, as an OEM supplier, you are required to follow. 1.2.2.9.1 states: "the level of initial process capability or performance shall be determined to be acceptable prior to submission for all special characteristics designated by the customer or supplier". Whether it was overlooked or not, the initial process studies were required unless you have a specific customer waiver.

As to the requirement to continue monitoring the process, look at 8.2.3.1 of TS 16949 which states "The orgaization shall maintain manufacturing process capability or performance as specified by the customer part approval process requirements" which in this case is the process capability determined by the Initial Process Studies in PPAP.

As to the sampling strategy, I am afraid I can't offer much. The obvious would be to run a control chart on a characteristic that would give you confidence the process was running as it should. The data collected would demonstrate the capability and stability they are looking for. If you already take a measurement for in-process control, maybe you can use that. I would need to know more about your process and product to make any other comments on what might be appropriate.

Dave

Should we monitor all Significant part Characteristics with SPC?

If so, what is a good sampling strategy to assure the process is stable and under control?
Assuming you want to monitor the characterisics, and ignoring the discussion of the validity of the opinion of the STA, here are some thoughts:

1. Is it data you are collecting anyway? If not, how expensive/ time consuming is it to collect?

2. As far as making the SPC, the cost of that is negligible to the cost of the data. If you have the data, why not plot it on a control chart for the record?

By the way, at Hanford I am on an upward trend again with chart making. Broke the 2,000 mark in December (which was above the UCL), and made 2,126 charts and files in January (up further due to quarterlies). Takes about 15 seconds to update a SPC chart.

Thanks for all the good comments. The OEM needs very few of these service parts. We'll batch run 300 and build an out of fashion just-in-case inventory that's good for 5 year of customer demand. The part is simple, we machine a rough casting and press in a seal.

At PPAP did an initial 5 piece run and inspected 6 ballooned dimensions which the customer signed off on. When we set up and run the part again we do first piece inspection to the ballooned drawing. We didn't quote monitoring the SC's during production with SPC or charting with control charts.

Thanks for all the good comments. The OEM needs very few of these service parts. We'll batch run 300 and build an out of fashion just-in-case inventory that's good for 5 year of customer demand. The part is simple, we machine a rough casting and press in a seal.

At PPAP did an initial 5 piece run and inspected 6 ballooned dimensions which the customer signed off on. When we set up and run the part again we do first piece inspection to the ballooned drawing. We didn't quote monitoring the SC's during production with SPC or charting with control charts.
There could be a commitment by reference in the contract, though. For example, if the contract states that the requirements of customer standard #123 are applicable, then everything that's in #123 is part of the contract. If there's a referenced customer requirement or standard to do control charting for SCs, then you should have been doing it from the git-go, and your customer might be able to enforce the requirement now.

Right! Woulda, coulda, and shoulda are all nice to contemplate as we sit at our computers, but wslabey is on the firing line NOW and needs some workable advice.

("Woulda, coulda, and shoulda" all refer to the point when this whole issue might have been avoided IF it had been caught in Contract Review)

My first advice is to follow Steve Prevette's suggestion and look at what the added cost of compliance to this pissant STAR (Supplier Tech Assistance Rep) and his new (to you) requirement will be for your company. It may well be the cost of compliance at no extra charge to the customer may be worthwhile tuition to protect yourselves next time.

My second advice (if the cost of compliance without compensation is too high) is to involve your suits in negotiating some sort of compromise with the suits who are higher on the totem pole at the STAR's shop, given the circumstances of small volume, etc. Every OEM has a mechanism to make exceptions to its "rules."

Wes,

Thanks. 3 weeks have passed since your last comment. We met again on the issue.
We have decided to dispute this with STA when she returns for another site visit about both the change of heart so to speak and some additional requirements of the raw casting we receive from the OEM. (By the way, this part is not a real money maker but you take these jobs on to help the customer who is in a bind and needs service parts machined from castings made years ago and shelved at the OEM and shipped to us for machining and pressing in a seal ) So here is the additional concern I am reading from the latest STA writeup. The STA also wants us to request sub-supplier documentation and compliance SC's on the raw casting that we don't even touch when we machine and press in the seal. They are truly pass-through characteristics. I will attempt reasoning with her. If not, then we'll have to go over her head to a more reasonable person or consider dropping the program.


Right! Woulda, coulda, and shoulda are all nice to contemplate as we sit at our computers, but wslabey is on the firing line NOW and needs some workable advice.

("Woulda, coulda, and shoulda" all refer to the point when this whole issue might have been avoided IF it had been caught in Contract Review)

My first advice is to follow Steve Prevette's suggestion and look at what the added cost of compliance to this pissant STAR (Supplier Tech Assistance Rep) and his new (to you) requirement will be for your company. It may well be the cost of compliance at no extra charge to the customer may be worthwhile tuition to protect yourselves next time.

My second advice (if the cost of compliance without compensation is too high) is to involve your suits in negotiating some sort of compromise with the suits who are higher on the totem pole at the STAR's shop, given the circumstances of small volume, etc. Every OEM has a mechanism to make exceptions to its "rules."

One other thing to keep in mind. If the negotiation with the higher ups at the customer is difficult, there are numerous advisers like me who will come in and sit as "second chair" to your suit to advise and counsel during the negotiation to work out a livable compromise. (Some of us even clean up good and have good table manners.:rolleyes: ) Often the net savings, including saving the customer for future business, far exceeds the adviser's fee. You want your own suit in at the negotiation as the lead because it gives him/her credence at the next showdown, plus he gets to "take the measure" of the suits at the customer. [couldn't help the play on words]

One other thing to keep in mind. If the negotiation with the higher ups at the customer is difficult, there are numerous advisers like me who will come in and sit as "second chair" to your suit to advise and counsel during the negotiation to work out a livable compromise. (Some of us even clean up good and have good table manners.:rolleyes: ) Often the net savings, including saving the customer for future business, far exceeds the adviser's fee. You want your own suit in at the negotiation as the lead because it gives him/her credence at the next showdown, plus he gets to "take the measure" of the suits at the customer. [couldn't help the play on words]


Wes,

Thanks, but I already have the ear of the higher ups so to speak when I spoke to one of them regarding what's right and wrong with some of the STA's this OEM has in the field. He wanted me to give me the STA's name so he could fix the problem. We will try to work it out amicably with the assigned STA and only elevate if we have to should the negotiations prove futile.

Wes,

Thanks, but I already have the ear of the higher ups so to speak when I spoke to one of them regarding what's right and wrong with some of the STA's this OEM has in the field. He wanted me to give me the STA's name so he could fix the problem. We will try to work it out amicably with the assigned STA and only elevate if we have to should the negotiations prove futile.
You are much kinder (forebearing?) than I would be in your position. I would present it as an "opportunity to learn" for the STA when I approached the higher up at the OEM, but I wouldn't delay another minute. The problem is not the individual STA (Deming being channeled here), but the training and understanding of the "big picture" which has been communicated to the STA by the STA bosses which needs to be corrected. It may well be this is the only STA in the entire organization that thinks this way, but I doubt it.

You are much kinder (forebearing?) than I would be in your position. I would present it as an "opportunity to learn" for the STA when I approached the higher up at the OEM, but I wouldn't delay another minute. The problem is not the individual STA (Deming being channeled here), but the training and understanding of the "big picture" which has been communicated to the STA by the STA bosses which needs to be corrected. It may well be this is the only STA in the entire organization that thinks this way, but I doubt it.

Wes,

You are right on. Deming flashed before my eyes as well. Early in my career I was lucky enough to work with Deming with him as our quality consultant. I am not a chosen disciple but simply a man humbled by his legacy and insight. Almost 15 years later we met again when he taught one of his seminars in an office space we shared with another major compnay. I could see his was tired and was able to give hime my office and my office chair to nap in during lunch. He was just a relenting in his lectures. What an amazing man.

Back to the issue at hand. The dialog with the higher up was centered on the systemic problem that such behaviors seem to be evidence of a dysfunctional pattern rather than an isolated incident.

Just to give another point of view on this topic, I've run into the same situation more and more recently....existing customers with new SQA's/ProjEng's, coming to me with more and more requests (or demands) that differ significantly from what was previously promised (and delivered) and all of which will cost me substantially in time, effort and other resources.

In many cases, I have discovered that the SQA/PE has a new checklist, and are not prepared (or allowed) to deviate from it.

Another case where blindly following the requirements of QS/ISO/TS/whatever causes more harm than good.