In Product Master of APO you see 4 types of Procurement:
1. E- Inhouse -- If the the product is produced in the Plant
2. F - External-- if the product is procurred from outside the plant (either from the vendor or from some other plant)
3. X - Both Inhouse and External--- Blend of the above two
4. P-- External Planning-- If the Product is not planned in APO
External procured items are maintained for items such as raw materials, spare parts, intermediates, semi finished goods wherein those items are procured externally from a vendor or a supplier
In house production items are maintained for items produced inhouse or within a plant. This will be maintained for items like bulk items, non-sku items,
Hope this answer your query.
R. Senthil Mareeswaran.