01 Oct Useful Tips for Using RFID for Field Service Management
Editor’s Note: This blog post was updated April 30, 2018.
RFID (Radio Frequency Identification) is currently getting a lot of attention in the world of field service management, bringing the promise of real-time asset location information, error-free data capture, and the ultimate in efficient field service management processes. However, RFID technology alone is not going to solve all of your field service process problems. As with all promising technologies, it’s important to analyze the strengths and limitations to ensure that RFID will work for you.
First, it’s important to understand RFID technology and how it can be used in a field environment. There are RFID tags and RFID readers that need to be used together. RFID tags are attached to IT assets and can be “active” or “passive.” Active tags will initiate a signal, typically based on a timer, that basically states: “Here I am!”
Any RFID reader in range will capture that signal. Active tags require a battery, which makes them relatively expensive and limits lifespan to roughly 3 to 5 years. On the other hand, passive tags are activated by the signal of an in-range reader, which they respond to. Passive tags are cheaper and have a longer lifespan than active tags.
RFID tags can be used instead of simple barcode tags to track assets. RFID tags, however, are more expensive than regular barcodes. Passive tags range from $.10 to $4 per tag depending on how many you order. Active tags cost at least $15 apiece.
The following chart offers a comparison between passive and active RFID:
|Read Range||Up to 40 feet (fixed readers)|
Up to 20 feet (handheld readers)
|Up to 300 feet or more|
|Power||No power source||Battery powered|
|Tag Life||Up to 10 years depending upon the environment the tag is used in||3-8 years depending upon the tag broadcast rate|
|Tag Costs||$.10 – $4 or more depending upon quantity, durability, and form-factor||$15 – $50 depending upon quantity, options (motion sensor, tamper detection, temperature sensor), and form-factor|
|Ideal Use||For inventorying assets using handheld RFID readers (daily, weekly, monthly quarterly, annually). Can also be used with fixed RFID readers to track the movement of assets as long as security is not a requirement.||For use with fixed RFID readers to perform real-time asset monitoring at chokepoints or within zones. Typically necessary when security is a requirement.|
|Readers||Typically higher cost.||Typically lower cost|
Passive vs. Active RFID Comparison
The primary difference between passive and active RFID tags is that active tags are powered by a battery and automatically broadcast their signal, whereas passive tags do not have a power source and only transmit a signal upon receiving RF energy emitted from a reader in proximity of the tag.
RFID readers read RFID tags just like barcode scanners read barcoded tags. The difference is that RFID tags send out a radio signal that can be read without positioning the reader in a specific way over the tag like you do with a barcode scanner. So, it’s much easier to read an RFID tag.
Passive tags are read by bringing the reader “near” the tags (in order to activate them and read them), and it’s typically done by an individual walking around with a handheld reader or a reader that is mounted on a vehicle that travels around OR mounted to a gate of some sort that the tag travels through (for supply chain management, for example, where your items move often and in a very specific fashion). Active tags transmit on their own over a short periodic interval, typically to a wall- or ceiling-mounted reader that can be up to 100 feet away or more, depending on the range of the reader.
Using RFID in a Field Service Environment
RFID tags can replace barcode tags as the physical representation of an Asset ID on the asset or equipment itself. However, barcoding is still quite important for certain use cases, and you should ensure that there is also a barcoded representation of the Asset ID on the RFID tag as well.
The two primary advantages of using RFID over barcode scanning are:
- RFID tags can be read without requiring line-of-sight between the reader and the tag. This means that the tag can be hidden from view, placed inside certain types of items, and can be read from a variety of angles by a reader.
- An RFID reader reads multiple tags “instantaneously,” i.e., all of the RFID tags that are within the RFID reader’s range (which varies based on equipment and configuration) can be read at once.
Certain ITAM use cases are ideal for the RFID technology, namely:
- Physical Inventory: Regardless of whether you are using passive or active RFID, the ability to almost instantaneously capture all of the Asset IDs of equipment in a particular building or room is an incredible time saver!
- Mass Update Operations: Applying a status change (“Decommission”, for example) to all of the assets sitting in a specific room is much easier when performed via RFID, because you can identify all of the affected assets with a very quick sweep.
- Check-pointing: Tracking assets as they pass through a doorway or gateway of some sort is a very nice implementation of RFID. For organizations whose vendors pre-tag assets for them with RFID tags, this type of gateway can exist at the receiving dock, making it extremely simple to track when and where assets arrive.
However, there are also some challenges to be aware of when considering RFID for your environment:
- RFID tags cannot usually be read through metal or water materials.
- When reading a “room” or other areas, you cannot guarantee that your RFID reader will pick up every tag. For example, there is no way to tell if there are tags within the expected ranges that, for one reason or another, were not read (unless, of course, you already know exactly what tags are in the area). Because of this, you should test your RFID system in your environment to get a good feel of its limitations.
- When reading a “room” or other areas, your RFID reader may pick up miscellaneous RFID tags that you do not care about. Because of this, it’s critical that you create a pattern for your Asset ID RFID tags so that non-conforming tag readings can be ignored.
- Some RFID readers provide an option to read a single RFID tag by limiting the reader to the “closest tag” based on signal strength. However, it is nearly impossible to force it to read a single, specific tag, especially when assets are close to each other.
- When you use an RFID reader to read all the tags in the area, note that you will not be physically touching and confirming each item. If you have a requirement to physically see or touch asset, then RFID will not be useful for that process.
Use cases that are NOT ideal for RFID include:
- Creating an asset record
- Affixing and associating asset tags (whether Barcode OR RFID)
- Updating / MAC a single asset
- Physically verifying an asset’s existence
Because certain field service use cases are well suited for RFID and others are not, we strongly recommend that you incorporate a combination RFID / barcode scanning solution for field service management. Purchase readers that have RFID as well as barcode scanning capability, and include a barcode sticker on the RFID tag to support the scanning operations.
- Choose RFID over “just barcoding” when it is very important and / or very cost-effective to implement RFID-friendly ITAM workflows, such as:
- Gross-level, non-intrusive, location-focused physical inventory
- Asset checkpoints or check-in / check-out gateways
- Frequent “mass” updates (updating a large number of assets), such as moves, transfers, receives, ships, or status changes
- When using an RFID tag to identify an asset, just encode its Asset ID onto the RFID tag
- Always replicate the encoding of the Asset ID onto a barcode on the RFID tag, so that you still have the ability to directly scan a single unique asset identifier
- Always encode your Asset IDs with a well-formed pattern so that non-Asset-ID RFID values can be ignored during an RFID reading
- After designing your RFID-based ITAM workflows, test the areas/locations where the tasks will be performed
- Always assume a margin of error in your RFID readings, particularly near the perimeter of your reading range
- Complement your RFID solution with barcoding workflows for use cases where RFID doesn’t work very well
RFID can be a huge time and effort savings for many field processes! As with any technology, it has its strengths and weaknesses, however, so make sure that you have a good understanding of how it works to ensure a successful implementation.