CMM Time for PPAP
Randy Stewart said:
PPAP is costly, it is something that should be in the SOW and costed. If you automatically submit one, then you give the impression that they are free. There is no way that I could offer up the CMM time to do a PIST inspection or a 5 piece study on a door assembly. I would get killed tieing up the CMM for 10 - 14 hours at no charge.
Agreed, CMM time is costly and it has to be factored into your overall cost of doing business. Hopefully, the certainty it brings in terms of proving out capabiliity will, in the long run, be cheaper than not doing so.
In small volume programs we negotiate the sample sizes required for parts to be CMM'd and at which stages of development. We had one customer engineer who, if left unchecked, would have us CMM 30 parts in the initial tool trials, and again in pre-production and then finally for final tooling. Yikes, it got expensive, especially when it is small volume (5,000 units per year). We like to clarify those measurement requirements in the contract negotiation phase and statement of work.
Pricing PPAP as a line item that customer sees is usually greeted by the OEM customer quite negatively. It is kind of like waving a red flag in front of charging bull. Obviously, a full PPAP does have a fixed cost that needs to be recovered in the piece cost by either reducing defects, rework, scrap and customer ill-will. If, however, volumes are too small, and the mfg. process is already fairly capable, the added cost of full PPAP can and will erode the net contribution of the product to the bottom line.