Production Planning is the process of using forecast and customer demand to
create productin and procurement shedules for finished production and
component materials.
The overall manufacturing planning process is comprised of:
1, Sales & Operations Planning (SOP)
2, Master Production Scheduling (MPS)
3, Material Requirement Planning (MRP)
SOP uses forcast values and requirements from the sales information system
and costing/profitablility anslysis as inputs for determining planned independent requirements（独立需求计划）.
Planned independent requirements(PIR) are planned quantities of a product over a given period of
time.
MPS items(those items that greatly influence profits or consume critical resources（关键部件和产成品）) are planned.
Planning the MPS items separately leads to
(a reduction in stock levels) and (improved delivery performance).
MPS is an optional step in the planning process.
MRP is the final step in the planning process. The output of MRP includes a planned orders
or a purshase requisitions（请购单）.
The communication between SD and Production&Pecurement takes place via MRP.
