Truck Ind. customer requires PPAP's done to their requirements. No other customer requires PPAP. Since we can meet the customer-specific PPAP requirements, what else do we need to do to show QS auditors we meet the PPAP requirements. Do we have to do a PPAP (unsubmitted)to the book just to show we can?

Also, there are NO customer key/critical product or process characteristics. Do you have to do any capability studies, just to show you can do it if you have to?

1- Yes, you have to do a PPAP to comply with the requirement. refer to 4.2.4.1 of the QSR.

2- I interpret the requirement for Cpk as applicable to customer designated special characteristics, however, be prepared to discuss your case with the auditor,Cpk is part of the process of knowing when your process is in or out of control.

There is a claim by some customers that any parameter that you control becomes a CC.
In general I have only submitted CPK for CC on the customer drawing and have never had any problem with that.