Pretty much any WMS can work in a “paper-based” mode. This means you will print pick lists and putaway lists and hand them to a forklift operator who will execute the warehouse transaction based on what’s printed out. It seems obvious that a mobile terminal with barcode scanning capabilities would always be a much better solution, right?
Not necessarily. Mobile terminals often only make sense in certain situations. When thinking about terminals and barcode scanning, people often make the dubious assumption that everything that comes into their warehouse will already have a barcode label on it containing useable data elements. This is rarely the case. In the real world, product is often coming from various suppliers who use different label formats, print different data elements on their labels, and use different barcode symbologies. Even if the carton has a barcoded product code on it, what good does that do you? To perform a warehouse receipt, you will need to know many additional pieces of information including product quantities in the required unit of measure and data elements beyond the product code that may be necessary when picking (expiration dates, order numbers, lot numbers, etc.). Therefore, barcode scanning usually is only useful if you have access to purchase order data (either from your internal ERP system or via EDI) and have enforced consistent labeling policy for all suppliers. If that is not the case, the only other way to utilize barcodes is to re-label each case or pallet as in enters your warehouse. This can be expensive and labor intensive.
Hardware and set up of mobile terminals can be expensive. Terminals typically range from $1000 - $3000 each. If you opt for an RF solution, you will need to pay someone to do a site survey and install access points. Although most RF devices use standard 802.11 wireless technologies these days, installing wireless in a warehouse is a much different animal than putting a cheap wireless router in your house. Warehouses are often large and have many obstacles to good wireless reception. To get good wireless coverage in your warehouse, you may need many access points all of which probably will need to be installed on your ceiling (think lift truck rentals). A standard RF installation in a 50,000 sq foot facility can hit $10,000 pretty easily.
So with all these headaches, why not use a paper-based system? Here are several reasons that may lead you down the mobile path:
· Large warehouse with many workers. An RF-based WMS is generally going to be more productive than a paper-based system. For a small warehouse with a few workers, it probably doesn’t matter. But, for example, if your warehouse is 100,000 sq feet with 10 workers, RF will probably easily pay for itself in productivity gains.
· High velocity warehouse with real-time visibility requirements. If you have product going in and out of your warehouse very quickly, and stakeholders need to know exactly how many units are in your warehouse at any given moment, you may need an RF WMS. With paper-based systems, there is always a visibility delay between the time product is handled and the time the transaction is entered into the system. This delay in inventory updates may cause problems in your warehouse operations, or may simply be unacceptable for your business requirements.
· Severe accuracy requirements. If done right, barcode scanning from mobile terminals should increase accuracy of product handling. Without a scan, there is nothing to prevent a human from picking the wrong carton or from the wrong location. However with a scanner, the system will check his work and notify him of a mistake. This will reduce handling mistakes. If you are working with high valued goods, or sensitive products where a handling mistake can cause big damage, a mobile terminal solution with barcoding may make sense, even if your warehouse is small or low velocity.
There are really two ways to implement mobile terminals and barcoding: batch and RF. Batch terminals are usually little MS-DOS based PCs or Windows Mobile devices that work as autonomous PCs. They do not connect to your WMS in real-time over a wireless connection. The warehouse worker processes some transactions which store on the device, then uploads everything in a batch using a base station hooked to a PC. Given this, batch terminals will not necessary solve several of the above problems like real-time visibility any more than paper-based systems do. RF devices, on the other hand, are wireless and interact with your WMS database in real-time. Most WMS’s will support RF, but not all will support batch. This is because batch terminals usually need applications that were specifically written to work on that particular terminal. RF devices can work with terminal emulation or even as web browsers, so it is often easier to develop RF interfaces for a wide variety of mobile hardware.
The conclusion is that you have to think carefully about whether you really need mobile terminals to begin with. If there is any chance you will, make sure you find a WMS that supports this. Often mobile access is an add-on that you can purchase later, if you decide it’s necessary. That’s the best way to go.
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