Settings required for MRP run

Dear All;

We are a manufacturing company, with over 10 plants.

Only one of the plants does manufacturing then distributes to the rest through cross company transfers.

Each company individually plans its FG requirements and passes them the manufacturing plant in form of demand forecasts for the following month.

The manufacturing plant then plans for raw materials and production as per the requests.

We want to use Sales Operations plan (SOP) and MRP run to carryout the activities i have described above in the system.

Kindly advised me on the settings we need to make in the system in order to achieve this.

Thanking you in advance.

Richard.