Back flushing is nothing but automatic goods issue. System will automatically posts the goods issue when you confirm the operations.You have no need to make manual issue. It will reduce the effort.
Backflushing is automatic accounting (Goods issues - 261 mvt) of material consumed for production, at the time of confirmation. Eg. When a 4 wheeler automobile is rolled out from assy line, 4 wheels & Tyres are deemed to be consumed and issued to production order automatically by way of backflushing by the system.
Assembly line picks the material from stores/ Assy line and use.
No Physical issue & Manual posting ( Goods Issue) by Stores.
Backflush is used for material which are a must and having fixed relationship.
This can be configured in MRP2 Screen,Work centre, Routing and production order.
Each has some special function.
If you configure this in routing or production order you have no need to activate this in MRP2 or Work center screen.
MRP2 Screen defines whether material components are backflushed are to be made at the work center.