Demand Managment

Vantage doesn't isolate the production schedule from sales order
demand that exceeds the MPS quantity. This makes the function
useless for the purposes of leveling the load in the shop with past
due sales orders still driving MRP.

I'm looking for a solution that will allow me to isolate the
production schedule from sales order demand (like a master schedule
is supposed to do). Can anyone help me with a work around or a
software package that I might use for sales order entry and master
scheduling where I could upload a master schedule to Vantage? Maybe
I could use Vantage for backend manufacturing processes and another
software package for sales order entry and MPS?