AIAG starts off in Note 2, page 7 stating that initial process study is focused on variables not attribute data. It does not limit attribute characteristics as being key characteristics, it just claims that they are not applicable to short term capability studies. Now, customers may twist that to infer that they must be variable, but that can be shown to be senseless, as in my previous example. They claim it takes more time to collect data for attribute characteristics, so attribute data is not acceptable for PPAP submission - unless approved by customer. Of course nearly every section of the Initial Process Studies 2.2.11 awash in disclaimers that you "need to get customer agreement", because - quite frankly - even though they want to see capability indices, there are so many exceptions (such as 2.2.11.5) that AIAG does not want to commit to anything.