Considering Capacity Constraints for Inventory Optimization

 I'm implementing IO 11.5.10 for a client who owns hundreds of fast food restaurants from different chains and already has an Oracle ERP 11.5 with the PO, IM, WIP, MRP and OM modules. Right now I'm at the design-of-solution phase and because IO is new to me i'm having trouble finding where do the requiered data come from. The most crucial questions I have are these:

Where are the cost fields found in the ERP? (I understand these fields are critical in order for the optimal postponement to be calculated)

Where are the capacity constraints set in the ERP, all of them but specially warehousing resources? (where are they found in case the client does not has them populated)