Finite and infinite capacity planning

Somebody thinks that infinite capacity planning is just a limit of production planning software and its heuristics. At the contrary it has much sense.
Infinite capacity planning is for verifying the extra capacity requirements and only checking this we can decide to add internal capacity, buy outside
capacity or shift loads in time, maybe accepting delivery delays. So finite capacity planning/scheduling should always follow infinite capacity planning/scheduling.
Some APS packages, like Cowry, allow the users to combine finite and infinite capacity planning setting different constraints for different departments.
For example it is possible to plan upstream shops at finite capacity and downstream ones at infinite capacity, then adjusting capacity for the downstream
shop and finally calculate a single plan with both the
upstream and downstream shops at finite capacity.