This applies if the selected work center has been registered as a subcontractor, which will activate the column Subcontractor. This will allow you to select a subcontractor for that work center. You can configure default suppliers and references for your subcontracting work centers. Suppliers and references are established in the Update Work Center procedure. The default supplier will then be automatically entered in this column.
When printing manufacturing order documents, you can also print subcontract purchase orders and possible subcontract delivery notes to the supplier selected on the operation row. This requires that both documents have been defined in the Manufacturing Order Documents procedure in the Global Settings module.
When reporting a subcontract it is also possible to create a supplier invoice basis. This is determined by the setting Create supplier invoice basis during subcontract reporting?, under the Accounts Payable heading under the Purchase tab in the Settings procedure.