Tracking inventory accurately can require more than just stock counts. Many products can have lot, batch, or serial numbers attached to them — and properly managing these is just as important as monitoring your inventory levels.
Lot and serial numbers are tracked through the manufacturing process, delivery to retail stores, and right through to the final sale. In this post, we’ll dig through what each of these numbers represent and how you can effectively track them.
What are batch and lot numbers?
In this post we’ll mainly refer to lot numbers, but the terms “batch number”, “lot number”, and even “code number” can be used interchangeably. Lot numbers are used when you make a product in large quantities, with the same set of ingredients or raw materials, and at the same time. You’ll find lot or batch numbers commonly used in the food, automotive and pharmaceutical industries, and they can also help to track children’s products.
If there turns out to be a problem with a product, manufacturers can save a lot of money and effort to recall products based on lot number. For example, if a drug turns out to have a dangerous ingredient in it, a pharmaceutical company can examine which lots were affected and then recall them — instead of having to recall all of the bottles on all of the shelves.
If you end up having any issues with a product in your business, you’ll likely report it to a manufacturer with the lot number. The lot numbers are sometimes given a prefix (e.g., Lot 114321), but they may simply appear as numbers that are stamped or printed on the product.
Tracking batch or lot numbers
If you purchase products that have lot or batch numbers, record them as you receive them on each purchase order. Specifically, record how many units were received, as well as the lot number assigned to them. You’ll then want to store all units that share the same lot number in a single space for easy tracking.
It’s most convenient if your inventory system can record a lot number directly, but if there isn’t a dedicated space for recording one, you can also record the lot number as a sublocation. For example, if you’re storing a particular lot in Warehouse A, you can log its location as Warehouse A, Lot 345.
It may not be necessary to include the lot number on your invoices to customers, but you will want to track it on the pick list for each invoice. That way, if your customers process any returns due to defects, the pick list will help you quickly identify the lot number in question.
[inFlow Cloud tracks lot numbers using the sublocation field. For more details, see this sublocation article.]
What’s in a serial number?
While lot numbers refer to a group of identical products, serial numbers help to identify individual units of a product. In other words, they’re even more specific than batch or lot numbers. A lot number could be assigned to tens, hundreds, or thousands of identical products, but a serial number is only assigned to one unit. In other words, serial numbers make products unique so you can differentiate one unit from another.
If you take a look at the bottom of a laptop, you’ll likely find a serial number printed or engraved on it. If you don’t see it there, the number is often associated with your purchasing account at a retailer, and it will be printed on the original invoice.
Serial numbers can be used for recalls, but they’re also handy for service eligibility. Warranty and repair requests will often require a serial number submission before the services are approved, and the serial number will help to identify the date of purchase (because it’s usually included in the invoice).
Serial numbers can also contain more information about the product. The encoding can vary from company to company, but you can commonly use a product’s serial number to identify its model number, date of manufacture, and even a code for where that product was made.
Tracking serial numbers
If you sell serialized products, you’ll need an extra level of precision in your inventory tracking. When you receive your products, you’ll have to record how many units you received, as well as the serial number assigned to each individual unit.
This serial number will also be recorded on any stock transfers to other storage locations, and on any sales or returns. Entering long serial numbers after every product movement can be time consuming, so it can be helpful to have your serial numbers printed out as scannable barcodes. This way your staff can use a barcode scanner to scan how much of a particular product is being moved, and then scan a second set of barcodes to identify exactly which serials were included in that transaction.
We’ve heard from customers that they previously tracked serial numbers using complex spreadsheets, where each row would represent a product and its corresponding serial number. While these can work for smaller batches of serialized products, it can also be very easy to make mistakes and overwrite data.
We’ve designed inFlow Cloud to make this process easier. inFlow ensures that serial numbers follow serialized products through every stock transfer and transaction — from initial purchase to final sale. So you can rest easy knowing that your serial numbers are being tracked, but without having to resort to giant spreadsheets to manage them.
If you’d like to simplify serial number tracking, inFlow Cloud can help!