Welcome back everyone to another Fuzzy Friday. This week we are talking about serial numbers, which may sound a bit weird but it’s a hot topic at some of our projects and there are numerous ways serial numbers impact a warehouse operation, provided an operation requires serial number capture of course.
So let’s start with the easy stuff, what are serial numbers. We’ve all seen them, we’ve all dealt with them but what are they actually? Serial numbers are numbers associated with a single unit of a product to uniquely identify it. You can find them on phones, laptops, cameras, TVs, cars even. The VIN on your car is basically a serial number.
Why would we have serial numbers in the first place?
Frankly, they’re a hassle to record and track if I’m honest. I think we can all agree on that.
But what happens if your car contains has a major component that might cause it to crash? Well, the car manufacturer will check all the VIN numbers that would have that component and issue a recall to fix this. Instead of recalling every model of a certain car they can pinpoint it down to only those ones with the faulty component. The same applies to all the other items in the list above.
But what else would we use serial numbers for? Checking for counterfeit items with cosmetics or high-end fashion is a good example. And probably the most common one we all know about is warranty. If your phone dies within the warranty period you can go back and get it fixed or get a replacement. The manufacturer will use the IMEI number of the phone to validate whether it falls within the warranty period.
So, the short of it is, serial numbers have a myriad of uses. But why and how do serial numbers impact a warehouse operation?
The answer is actually quite simple. The warehouse is the one responsible for matching the serial number of an item to the end customer who bought the item. Somewhere in the process of receiving, putaway, replenishment, picking, packing, consolidating and despatching an item, the serial number has to be captured and matched to a customer order.
And this is where it can get tricky because depending on how your warehouse operates and what your WMS/ERP/IM system supports in terms of capturing a serial number is the difference between having a streamlined and efficient process vs an annoying and inefficient process.
I’ll give you a few samples of some of our previous and current projects to put this into perspective.
Before I do so I have to tell you that most operations we review do not capture serials upon receiving. They generally only capture them either during picking or packing. Some high-value items are usually the exception such as expensive TVs and Phones. They usually arrive with the serial number of the items on a pallet plastered onto an A4 sheet on the outside of the pallet for easy receiving and capturing.
One of our customers sells serialised and non-serialised products with the serialised products only consisting of 3-4 SKUs and the majority of orders consisting of only 1 serialised item. So they devised a process whereby they would store pallets of serialised items at the packing bench and run a batch pick of multiple orders at once after which they would add the serial number of each item during packing so they could print the despatch label, capture the serial and efficiently pick, pack and despatch large quantities. For any non-serialised items they would be picked from the DC using paper pick tickets, including a fake pick of a serialised item and add the serial number of the actual item during packing.
When they were looking for improvements and further efficiency they opted for a scanning solution bolted onto their ERP rather than a full WMS implementation, however, this had one big limitation which was that the bolt-on only allowed capturing of serials during picking, not during packing. They ended up forking out for a modification of the bolt-on’s packing process to allow for serial number capture. If they hadn’t, they would have suffered a major reduction in their efficiency. Just one simple example of how serials can really have an impact on an efficient process.
Another one of our customers handles phones. Now phones are slightly different because of the IMEI number capturing. In addition to that some vendors add an additional serial number to the phone and some vendors even have 2 IMEI numbers per phone just to keep it simple.
This customer runs a WMS which provides a serial number mask option which is helpful to ensure operators don’t accidentally scan the wrong barcode. It can be used for a length checks or a specific format of a serial number. For instance, an IMEI number is 15 characters and a retail EAN is 13 characters. The serial number mask would prevent an operator from accidentally scanning the EAN instead of the IMEI number. Another one would be whereby a serial number from a certain vendor would always start with “943” and be 13 characters total, the mask would require an operator to always scan a barcode starting with 943 and the total length would have to be 13 characters.
Unfortunately, the serial mask isn’t sufficient for this customer. Some of the secondary serial numbers are also 13 characters with no specific mask which is the exact same length as a retail EAN number, which also doesn’t have a specific mask and instances have been recorded whereby the operator scanned the EAN instead of the serial or the serial instead of the EAN. When they scan the EAN instead of the serial it results in a non-existent serial is recorded against the customer order losing all traceability and that the WMS rejects all subsequent scans when someone scans the same EAN again because a serial number has to be unique. This causes all kinds of clean up processes to be triggered and having to rectify the first scan of the EAN if it has already been shipped to a customer. And after the clean-up, it can happen again because there is no way to prevent this from happening. This specific customer resorted to putting up a huge sign for these specific products notifying operators to scan the right item, which reduced the number of instances but it’s not a foolproof solution.
So there you go, just some of the samples how serial numbers can impact a warehouse operation. They are not easy to deal with and they can cause a great deal of pain but they are necessary for certain products. You just have to find a way to deal with them somehow.