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

252 MFG/PRO USER GUIDE — MANUFACTURING
Tip
Typically, Net
Change MRP is run
daily.
Tip
The first time you
run MRP, it should
be regenerative.
Net Change Materials Plan
Net Change Materials Plan (23.1) calculates demand and plans supply
only for items that have changed since MRP was last run. These changes
could involve any of the following:
• Item or item-site planning data
• Product structures
• Sales or purchase orders
• Work orders or repetitive schedules
• Inventory
• Forecasts
• Master production schedule
• Intersite demand
In addition to planning items that have changed, net change MRP
recalculates lower-level requirements for items planned.
Both net change and regenerative MRP plan items based on low-level
codes. They determine requirements at the top level first, then continue
down through the item structure, one level at a time.
Regenerative MRP
Regenerate Materials Plan (23.2) recalculates demand and plans supply
for all items in the site. The outputs of net change and regenerative MRP
are the same. However, net change MRP generally runs faster than
regenerative, since it only plans for items that changed since MRP was
last run.
You should always schedule periodic regenerative MRP runs, even if you
primarily use net change MRP, since net change MRP does not consider
demand or forecast for items entering the MRP horizon over time.
Selective Materials Plan
Selective Materials Plan (23.3) plans only for items and sites you select. It
can be run in net change mode by setting the Required Items Only field to
Yes, or in regenerative mode by setting Required Items Only to No.