Initially, the Alternatives List for Product Structure is Empty. It means that reporting Production Order You can receive into Inventory as a manufactured Product only Part Number and Modification explicitly specified in the header of Product Structure. The Alternatives List can contain Part Numbers and Modifications for ANOTHER Alternative Products which can be also received into Inventory. The Alternative Products from prepared Alternatives List will be included automatically into each new Production Order for this particular Product Structure. Reporting Production Order, You can receive into Inventory ANY of them if it will be manufactured by accident instead of expected Product.