How to include Firm Planned Orders from Tactical MRP as supply in Operational MRP?

How to include Firm Planned Orders from Tactical MRP as supply in Operational MRP?

Business case

In the ETO environment I'm currently working, the custormer demand is accepted by checking the feasibility in an ECC Tactical MRP plan (respecting lead times). If the Material Available Date is after the NeedBy Date the lead time needs to be compressed. This is accomplished by firming selective bottleneck activities on the critical path (FPO's). We can't create discrete jobs since the sales orders/contracts are accepted years ahead (can be up to 5 years ahead) and are subjected to engineering changes.

The FPO' s of the Tactical MRP should be automatically included as supply in the EDD Operational MRP.