MFG/PRO 9.0 User Guide Volume 3: Manufacturing - QAD.com

226 MFG/PRO USER GUIDE — MANUFACTURING
line. Abnormal sales demand is added to the net forecast rather than being
subtracted from the shipment forecast.
Net Forecast Calculation
Master production scheduling and MRP use the net forecast and abnormal
sales order demand to calculate total demand. The net forecast is
calculated as follows.
Net Forecast = Forecast – Sales Order Demand
Note When the shipment forecast is oversold—that is, the quantity sold
exceeds the forecast amount, the net forecast will not go below zero.
Forward and Backward Forecast Consumption
Typically, shipment forecasts are more accurate over a month than over a
week. You can lessen the effects of inaccurate forecasts using forward and
backward consumption.
Confirmed sales order and required ship schedule quantities automatically
consume forecast in the week they are due. However, if there is no
remaining unconsumed forecast for that week, the system can be set to
consume remaining forecast quantities for a number of weeks before or
after that week.
You can specify the number of forward and backward weeks over which
to consume using the Consume Forward and Consume Back fields in the
Sales Order Control File (7.1.24). The system consumes forecast first by
going back, then forward, one period from the original forecast period.
Consumption continues alternately backward and forward until the
specified number of previous and future periods is exhausted. If there are
sales quantities still left over, MRP recognizes them as additional
demand.
MRP and master schedule planning recognize prior period unconsumed
forecast as demand for the number of weeks specified in Consume Back.
If the Consume Back and Consume Forward values change, the system
automatically recalculates the net forecast based on the changes.