BOM item qty does not change when header qty changes in Outbound Delivery

Hi,

We are using sales BOM and exploding it in Sales Order. ( Item category of components as TAE )

I am creating a delivery with reference to a sales oder ( i have maintained copy controls to copy header and item data). Now when i change BOM header quantity in delivery document system is not redeterming the components quantity , item quantity of the components does not change.

Please let me how can i control item qunatity when BOM heade quantity changes in outbound delivery document

Thanks

Venkata Rama Reddy.K