Barcodes allow an easy method of data capture. Normally they are a short sequence of alphanumeric characters that signify the particular product. Most barcodes in use are fixed and have a limited use in tracking systems. A determination as to where particular products should go is easy using fixed barcodes, but data regarding the particular batch of components cannot be determined from the fixed barcode alone.

To track other data along the route, needs a barcode that is unique to that item, then with the barcode alone, a trace can be made to determine the components origin or batch number or details of any other process the item has gone through.

Sometimes, multiple barcodes are used on items, the first may be the generic fixed barcode printed on the packaging and the second, a barcode printed at goods inwards to identify a part or batch particular to this item.

As the part is used through the system, a history is built of times and dates and operators. These part history records can then be used to investigate problems and to tie parts to goods inwards shipments easily and even the other way from a batch of parts to a series of completed products.
The extent of barcode tracking is purely dependent on the requirements of the individual system or range of parts.