Traceability allows you to assign a lot and/or certificate number to parts.
Lot numbers are manually assigned to parts. Lot numbers enable you to track a part, from the moment it was delivered to you until the time it leaves your company, whether or not as part of an finished product. Also parts produced in your company can be assigned a lot number. Lot numbers make it easier to locate a part with a particular lot number.
Some suppliers want or need to guarantee the quality of their parts. They do so by assigning certificate numbers to their parts. If you register the certificate number for a batch of goods, you can always trace the certificate and supplier of a part used at your company. You can also see what the part has been used for. This allows some form of quality assurance, as you could, for instance, check whether problem-prone parts always originate from the same supplier.