Consume components, produce finished goods, and keep the stock ledger honest.

Operations → Production → BOMs → New. Pick the finished good and list every component with its per-unit quantity.
New → Production Order. Pick the BOM and the target output quantity. The system reserves the required components from stock.
When the batch is done, confirm the order. Components are consumed (stock-out movements) and finished goods are added (stock-in movement) — all against one parent reference.