We have implemented Oracle Advanced Supply Chain Planning! It was hell and constrained planning still does not work as we would like it. Somehow the system does not generate the planned orders according to the supplier constraints. We have had some TARs but Oracle did not yet come up with a solution.
The idea is to have the suppliers upload their production constraints into our planning system using a couple of custom webpages (supplier commits). Planning system should then create planned orders using that information.