PP Production Order What is Backflushing?

Can anyone tell me what is backflushing for? When is it use?

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.

Assy 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.

When we do the back flush the backlogs are being created for the BOM components and we are getting the message "Backlogs from backflush were created or changed" - its just an informative message. Do you think this has got something to do with the negative postings ?

Backlogs are created due to different reasons.

This message tells that "there is no sufficient stocks for the bom component/not able to backflush all the material due to plant data locked etc" at the time of backflushing the BOM Material and hence the Post-processing list is created that you have to Re-process for stock updation of each material.

To avoid this you can confirm the following things.
1.Ensure that suffecicient stock is available in the backflushing locations of each materail.
2.To prevent the generation of "post-processing list" you can block the BOM from getting backflushed if sufficient stock is not available in specified location for the BOM COMPONENTS. To do this change the "REM profile" to "002"in MRP4 view for the BOM MATERIAL.(if the profile is not available you can crate it through SPRO).
3. To clear the existing Backlog use transcation MF47 and re-process(be ensure that required stocks is available for each bom component)