RF Strategies

The most popular post on this blog is Warehouse RF Network. If you do a Google search for Warehouse RF it is the number 2 result. How we got to that spot I'm not sure, but there we are. A lot of the organic traffic that we get comes in through that post. Looking at the search terms that drive people there it seems that RF networks in warehouses are one of the biggest questions that people have when they go about setting up a new facility.

RF is one of the fundamental blocks of an efficient warehouse. It is the driver of so many "Best-in-Class" style processes that it is simply foolish to not implement it. The cost has come down over the many years since it was introduced that it should be part of any operation. However as is the case with most technology, a lot of operators are confused by it and what needs to happen to implement it.

When it comes down to it, an RF Warehouse system is not all that different from your at home wireless network. Most of the general equipment is the same in concept, simply bulked up to industrial grade. The real difficulty to RF is getting the right software and processes around it. Picking a WMS is the hardest part really. There are now so many options for Warehouse Management Systems that going through them to find the best for your situation can be a truly daunting task.

The trick to RF is making sure that the planning around it is complete. Follow these steps and you’ll be well on your way to putting in a very strong solution:

1. Implement a reliable WMS system
2. Setup a warehouse map and picking rules
3. Develop new putaway and picking processes to leverage the RF and WMS systems
4. Train all warehouse employees in detail on how to use the system
5. Perform a complete inventory count
6. Activate the system

The difference between RF and a paper system is, at the simplest level, the interface. Everyone you would employ in your warehouse is familiar with paper and how to work with it. There is a mindset about RF that it is more complicated because it involves a lot of technology. The truth is that the technology is now developed to the point where it is highly user friendly.

Lately when the topic of RF comes up, the natural follow-up becomes “What about RFID?” RFID is the next generation of Radio Frequency. There has been a lot of investment by organizations trying to push RFID as an efficiency driver. A lot of people know by now that Wal-Mart dictates their suppliers use it and the US Military has adopted it for inventory control as well.

What you probably haven’t heard is that even Wal-Mart is having a hard time driving their suppliers to RFID. They just recently began imposing a $2 per pallet fine for every pallet that comes in without RFID tags. The implication of course is that there are quite a few pallets coming in without it. Why aren’t companies moving towards it? Why is it always on the horizon as the next big thing without actually hitting? The simple answer is that the cost to implement continues to refuse to drop. Technologies usually drop in price as they become more widely used, RFID isn’t.

If you have any questions about these systems feel free to give us a call or send us an email. We are here to help you understand how to make these systems work for you and your company.

Warehouse RF Network

It is becoming more and more common for warehouses to have an RF or wireless picking system. The advantages of the system outweigh the initial costs. Increases in productivity, inventory accuracy and order visibility reduce overall costs every single year as the warehouse becomes more adept at using the system. However the installation of the system has become a point of question to many looking at RF. Who should design the system? How do I know what I need? What am I missing?

Having built and fit-out several warehouses with this technology it is not going to be as bad as you think from a design and installation point of view. The key to a successful system install is to team with a quality and knowledgeable IT and Data Wiring vendor. Whichever vendor you ultimately select should have the ability to layout and procure the IDF cabinets, Access Points, wire pathways and all other equipment. They should know the proper specs and ranges for all of the equipment they recommend and should give you an electronic drawing of everything in your warehouse.

There are several aspects to an RF system that you will need to decide. The first is what kind of bar code technology will be used on products and locations. Wikipedia has a page describing the many types of bar codes that exist and their many uses. Most handheld scanners have the ability to read multiple bar code types, but it is still important to coordinate and make sure that everything is compatible from the bar codes to the printers to the scanners to the WMS. If you receive product from other vendors they may already have their own standard that you can use. Check with them if you are thinking of matching their technology.

In the typical warehouse there are many ways that bar codes will be scanned and many obstructions that could interfere with the wireless signal. Rack in particular is the biggest issue with warehouse RF. It is important to take into account several rack related RF issues during your strategy:

1) Lift Equipment Scanners - Vehicle mounted RF or Handheld units. Forklifts present several issues of their own. Vehicle mounted RF is typically more robust, more difficult to steal and more difficult to drop and break. However there is the additional cost to mount it to the forklift and you don't have the flexibility to use the scanner for floor picks.

2) Lift Equipment - Man-up forklifts or Man-down forklifts. The type of forklifts used in the warehouse come into play with where location tags can be placed on the rack. For man-up forklifts the tags will go directly underneath the product on the beams. In man-down environments the tags will have to all be placed on the first or second level to allow scanning. If there is a mixed environment there could be room for quite a bit of confusion.

3) Rack Density - The more packed together the rack in your warehouse is the harder it will be to get a clear signal to every point a scanner could be used. For a density of one pallet every 4 square feet you will need to have the wireless access points much closer together than for a density of one pallet every 7 square feet.

4) Rack Flexibility - If there is the ability to add and remove pick levels or locations there will be a need for a more flexible labeling scheme throughout the warehouse. The most flexible scheme I've come across follows the AA-12-34-56-78 format. AA stands for the rack type or forklift used to pick and putaway in the area. 12 is the aisle, 34 is the bay number in that aisle (odds and evens should be on opposite sides), 56 is the beam level within the bay and then 78 is the location on the beam. (ex. SS-23-34-02-02 would mean the location is in the Single Selective rack on aisle 23 in bay 34 (with evens being on the left) 2nd level up and in the right hand position.)

Once all of these issues are decided it is time to work with the IT vendor to actually develop the design. Don't stretch any of the equipment you get to its maximum range. Your IDF cabinets will likely be about 250 ft apart. Your access points will be staggered throughout the building on about 100 ft to 150 ft centers depending on rack density. With a 500,000 sf building your probably looking at a 400 ft depth which gives you two rows of IDF cabinets running along your building and 3 rows of access points. There are a lot of items that need to be coordinated so much sure you develop a robust plan for what you want and need this system to handle.


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UPDATE:

There has been a lot of interest in this post. If you have any additional questions feel free to email me at dmusic [at] integratedstrategiesinc [dot] com .



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