Missing parts for Production

Hi PP Experts,

Our client having ECC.5.0 and is not using MRP for material procuremnt.

In PP they are using the master datas Material master and BOM. In shopfloor, for sub assembly and assembly they will create production order (CO01) and MB31 for the goods receipt.

When the demand comes they will physically check all required material in store and procure the shortage mitems.

In most of the cases they are procuring sub assemblies and assemble to make the finish product.

Now they need a way to figure out the missing parts from SAP before creating a Production order.

Do you have any suggestion inorder to develope a report where the user will input the material number (for the finish product ) , production quantity and production date in the selection and the output will give the missing item and quantity based on production quantity.Here the availability will be checked only in the store.

Thanks in Advance

Pradeep