Hi Denis,
Your question is ok, the space (SAP PP) is also correct, what is not soo good is the subject 
.
Your problem is commonly managed through the process and not through the system.
I have seen in many company daily meeting (30 min meeting) between the planner, the production scheduler and the production team) in which the planners communicate the list of orders to be produced in the day and review the more relevant issues. You can do something like this.. it is not necessary to have daily meeting, could be weekly.. depend on your needs.
Note that the planner is responsible for the replenishment on time of the material in the corresponing plants, taking care of the inventory levels and deciding what are the priorities. They can change the schedule. Now if this generates a problem to the production process, you should negociate a frozen period in which the don't change the scheduled orders.
Kind Regards,
Mariano