Part 1
Course reading
In subcontracting, you send components to a supplier who makes the finished part for you. The components stay in your books as "stock provided to vendor" (special stock O), transferred with movement 541. When the finished goods are received against the subcontracting PO (movement 101), SAP automatically consumes the components at the vendor using movement 543.
Sometimes the vendor uses more or less component than the bill of material says — scrap, yield loss or a better process. SAP handles this with subsequent adjustment (MIGO → Subsequent adjustment, or ME2O / transaction MB04 in older releases). The adjustment posts extra 543 consumption (or a 544 reversal) against the original goods receipt so the vendor stock matches reality.
Manual 543 consumption without a goods receipt should be avoided: it breaks the link to the PO and the cost of the finished part. Always tie consumption to the subcontracting PO and its receipt.
Example: the BOM says 2 kg of steel per bracket. You receive 100 brackets, so SAP posts 543 for 200 kg. The vendor reports 210 kg used due to cutting scrap. Purchasing agrees, and a subsequent adjustment posts 543 for another 10 kg. The vendor stock drops by 210 in total and the bracket cost includes the real steel. KPIs: vendor stock accuracy, component variance per PO and age of stock at the vendor.