SAP PP MRP Reservation Not Created During MRP Run

I have created a planned order thro MRP run, but reservation for raw material is not created, even though stock is available. After conversion to Production order reservation is created. After confirmation and goods reciept MB31 final product is updated in storage location, but raw material quantity is not reducing.

Can any one give solution for this.

Gururaj Hebbar

PART I

After MRP run, based on the demand Planned order will be created and for the BOM components sytem will create dependent requirement if stock is available. If stock is not available system creates a planned order or a purchase requistation. Once the planned order of the Header material is converted into a production order , then system converts the dependent requirement into reservations.

PART II

After confirmation and goods reciept if the item components are not consumed, it means you have not defined backflush process. If you want to issue manualy to the order u can use T-CODE MB1A, for the same.

1. Check backflush indicator either in routing /workcenter or in material master.
2. In customization production control -operations-confirmation ( general individual entry screen ) check-- post open reservation . It will post open reser