Many businesses require a certificate of conformity (C of C) from their suppliers and vendors to ensure a product meets all defined requirements and to maintain paperwork traceability, which is important for many critical parts and systems. A certificate of conformity is defined as "a declaration by the supplier to the acquirer that, apart from any identified and approved concessions, the products conform to contract requirements," says the U.K.'s Ministry of Defence Acquisition Operating Framework website. Many suppliers ship products with a certificate of conformity as standard practice, but if not, it is possible to obtain one in other ways.
Inform the supplier that a C of C is required with all shipments when placing an order for the product. Most suppliers will be happy to comply.
Add wording to your purchase orders to require a C of C with shipment.
Check that a C of C was included with the shipment when the product arrives from the supplier. If not, call the supplier and request a C of C to be sent to you via mail, fax or electronically.
Contact the product supplier if a C of C is needed for a past order, even if one was not needed at the time or specified in the original purchase order. Many suppliers keep purchase order and manufacturing information for three years or longer and would be able to create a C of C to meet your request.