Outstanding and Completed PO in MM

Dear forumers,

An outstanding PO is defined when a storekeeper has not done goods receipt and / or the account department has not done their invoice receipt.

A completed PO is defined when both goods receipt and invoice receipt have been completed for the PO.

How can I check for these conditions from the MM tables in the ABAP Dictionary? Which combination of fields can I refer to for this? I cannot simply rely on the EKBE-ELIKZ (Delivery Completed) field, can I?

Please help. Thank you!