Originally Posted by flyerCO

Yes. They check that you have a BP. They check and run your passport to ensure its valid for destination. They also ensure your luggage transfers. 10-20 minute wait isn't uncommon. There's times no one else is there. While no waiting, it seems they work slower then.

Basically even if everything was on-time (which never happens in China due to military having full control/priority of airspace) I would give this zero percent chance of working with 90 minute connection. You'll arrive at a bus gate (very common at PVG), the buses will take a bit, the transfer process will take a bit, there'll be a line for security (which is the same checkpoint as used for originating passengers), finally you'll be departing from a bus gate or the furthest gate from security. You would need to be on time and have all those things I listed not happen, and even then I'd only give a 10-20% chance of making it.