Hi Chad:
4.9.2
"The supplier shall maintain (or exceed) process capability or performance as approved via PPAP."
I don't think it means exactly that which you are asking. There are requirements in the PPAP manual, (1.33, for example) and I think that is the "...maintain or exceed..." that they are talking about.
Also, as you continue to read 4.9.2, it mentions that suppliers will include containment of processes that are not capable.
If one wanted to read into this, one could infer that if your initial PPAP was the result of good
APQP type activities, you eliminated most or all of assignable cause variation during APQP activities, you also reduced common cause variation to the point that you are now capable, you have established the capability bar. Now, under status quo conditions, nothing should change regarding capability. AND, through continuous improvement activities, you have further reduced common cause variation so that you are now more capable.
Now, Chad, I can interpret "...maintain or exceed..." to mean what you said.
Comments?