Traceability, tracking serials, lots, and packs

A warehouse cannot be managed efficiently without having traceability in place. Assume that you buy laptops of the same brand in bulk from different dealers and you're selling them to your customer in a retail business. A customer comes with a complaint about the laptop and asks for a replacement. How can you verify that the laptop is still under warranty or not? Which supplier should you contact and ask for a replacement? If you have not maintained the tracking with a laptop serial number, you will not get the correct supplier from where this defective laptop comes from.

For the manufacturer, it is compulsory to manage the serial numbers or lots of the consumed items and assign a new serial or lot number for the manufactured items so that both way tracing is possible. For example, what is the raw material used in the manufacturing item and where does it come from? For the trading or retail business to keep the tracing based on the serial or...