The Problem with RFID
Realtime location and identification is one of the leading global trends, in part driven by the disruption to global logistics caused by the Pandemic. Global Retailers such as Walmart and Decathlon now mandate that all product get shipped to them with RFID tags on them. RFID has however been hard to establish in New Zealand for 2 reasons:
RFID options have historically been bespoke and very expensive, so was only pursued by the largest organisations in very narrow use-cases. Organisations were limited to the functionality of existing RFID based applications (e.g. for asset management, sterilisation, laundry), resulting in an expensive proliferation of applications. Alternately they had to build and support their own RFID applications to accommodate their workflow.
RFID is not like other IT technologies in that it requires electronics engineering skills with a specific focus on RFID and needs to be designed for 100% readability. A default IT approach will fail to deliver results that meets the organisation’s needs. The necessary skills were scarce in NZ.
Changes in both technology and economics means RFID is now more accessible and relevant for all businesses. Zebra, the global leader in location technologies, has resolved these challenges through the availability of their rules engine that can automate general location-based workflow when integrated with existing systems. The software is called MotionWorks Enterprise (MWE) and is available through their certified business partner in NZ, Synergic Technologies.
Understanding the Building Blocks of RFID Solutions
There are several building blocks that make up an RFID solution.
1
Rules Engine: Large organisations or supply networks need a single RFID rules engine (MWE) that handles all the RFID and even other location (e.g. GPS) or identification records (e.g. barcodes). The reasons are:
Most location-based workflows can be coded within the rules engine when also using integration, obviating the need for lots of specific applications or expensive software development. This engine turns the trillions of presence notices into system records or exception alerts. A normal database cannot handle such RFID records and the common IoT engines such as Amazon or MS offer do not offer an integrated rules engine, alerting, integration, asset management, device management etc.
The collated data is essential for any advanced analytics or workflow improvement. It is hard to know what data we will need till will need it. The data will also become even more important as the use of AI increases.
The exact location and movement can be represented on a map of the facility or the area.
The benefits will only increase as the vendor (Zebra) continues to invest in new features and incorporates emerging technologies such as other sensory data (temperature, humidity, volume, pressure, torsion etc.)
The lack of an enterprise rules engine often hampers the expansion of point RFID trials beyond that trial or use case.
2
Passive RFID is a close proximity and generally interior technology. It is used on bulk items such as inventory, anything requiring accurate identification, items that have to be rapidly located (to within a short rage), or anything that needs to be tracked in and out of locations or through a staged process.
The Tags are comprised of a chip that contains information, an antenna, and a housing. It is worth noting that many global retailers like Nike already ship their products with RFID tags embedded. Housings for the RFID chip and antenna exist or can be created for most use cases e.g.
Labels on which barcodes are printed. These cost single cents and are usually used in place of such barcodes.
Stainless autoclavable tags used for large devices such as trolleys that need to be sterilised (c. $20)
Inert glass tags that can be swallowed or embedded subcutaneously
Micro tags for surgical equipment
Zip tags to seal and identify bags
While some passive tags can be read more than 10m away, most passive RFID use cases are designed to operate within 5m.
Fixed Readers constantly excite RFID tags within range, resulting in radio frequency emissions, which are picked up on antennae. These are placed at choke points and allow tracking through a portal (door), or to and from a zone such as a ward, theatre, sterilisation facility etc. The engineering to select the correct tags, select, orient and tune the antennae need to be exact to ensure 100% readability of the tags given environmental factors. This is another area where a general IT provider will usually fail to deliver. Understanding the detailed workflow implications is also critical.
Zebra FX9600 Fixed Reader
Handheld readers cause nearby RFID tags to respond when triggered and helps with:
Locating a product or item
Accurately identifying an item
Rapid, bulk stock takes / cycle counts
Zebra RFD40 Handheld Reader
Array Readers are omnidirectional fixed readers that can triangulate the exact position of a tag to within a few centimetres. They work best in large open areas and require one reader for every ~120m2.
Zebra ATR7000 Array Reader
3
Active RFID Tags have a battery that constantly cause the RFID chips to signal.
Zebra Active RFID and BLE Tags
BLE Tags (Bluetooth Low Energy) are the most common of these and are usually used to capture the presence of people or assets near a reader (room level). Low cost temporary tags are ideal for patients, whereas longer lasting tags are ideal for permanent assets ($25-$80 per tag) or staff. High value assets are often tagged with passive tags as well in order to track movement too.
Wi-Fi Access Points (AP) already in place can serve as readers. The main brands (Aruba, Cisco, Extreme etc.) now come with the ability to pick up and pass along such BLE signals, obviating the need for special readers. The IoT and BLE over Wi-Fi protocols have not yet stabilised so will continue to undergo flux, which will require testing and development.
BLE Receivers are available at low cost (<$100) from the vendors to supplement the APs and provide points of presence.
Other Active Tags such as UWB, WhereNet etc. tags are usually used in longer distance (up to 1km), wide open, outside areas. The tags are even more expensive than BLE tags so the business case only stacks up for large volume, high value items.
Active tags are less dependent on accurate engineering and have lower infrastructure (reader) requirements, however while it is cheap to prove the technology works in a trial, the business case for a full deployment often fails purely on the cost of the tags and the battery maintenance. For interior use cases where the volume of tags is high, a passive RFID solution is much more cost effective and usually provides more useful data due to its high fidelity.
Note: The outside Active RFID market is being disrupted by mobile GPS and yard automation.
4
Functional Applications running on a commercial mobility platform (PDA, phone or tablet) allow users to interact with the system e.g. when locating an item, performing cycle counts or nesting products into a shipment. The global ERP, WMS and MRP products are RFID ready (TMS less so). While Zebra have an MWE app with many common functions, it is often best to work with the vendor to test their RFID readiness. The key change from barcodes is that RFID required each item to have a unique ID whereas barcodes do not.