A supply chain requires
seamless flow of goods between the point of origin and the point of
consumption, in order to meet the requirements of consumers. Physical
tracking of merchandise in a supply chain is a challenge today. Visibility into
the logistics network is critical to ensure optimal inventory level and better
co-ordination of different stages / departments in a supply chain. Automatic identification techniques like RFID makes this
process faster, more efficient and
accurate.
Radio Frequency Identification(RFID) is a reliable and
fast growing automatic identification
and data capture technology, which allows for non-contact reading to track and
monitor physical objects like retail items, vehicles, documents, people etc . As
it makes use of radio
waves for identification, RFID doesn’t require ‘line of sight’. A reader
communicates with a tag, which holds digital information (e.g., a serial
number) in a microchip. The microchip, attached to an antenna, picks up signals
and sends it to a reader. Each tag contains a unique serial number called the
Electronic Product Code (EPC) and the antenna enables the chip to transmit the
identification information to the reader.
RFID Tags
Tag is a an electronic device which uses radiofrequency
antenna to communicate with the RFID reader. Information is stored
in the tags as digital data that describe the object. Tag can contain large amount of such information and
also can write information into it at any point of time. Hence it is getting
more popular in supply chain and other industries too.
Tags can be active or
passive. The active tags are self-powered whereas the passive tags use the signal
from the RFID reader as the source of power.
Active tags use a
battery-powered transponder that emits a constant signal containing identification
information. Active tags have the greatest range of all RFID tags, including
search and read/write capability. Today, they have up to 128 Kbytes of storage
space, but could hold more in the future.
Passive tags have no battery,
but instead rely on an antenna as the power source, drawing power from the reader’s
electromagnetic signal. Passive tags have a much more limited range (less than
2-3 yards), have limited storage space (as of now, 128 bytes, but could hold
more in the future), and lack data manipulation capabilities.
The RFID tag responds to the
reader by broadcasting its EPC, which is a 96-bit code consisting of
Ø 8
bits of header information.
Ø 28bits
identifying the organization that assigned the code
Ø 24
bits identifying the type of product.
Ø 36 bits
representing serialization information
for the product
RFID Reader
RFID tag readers are devices
that scan the tags and decodes/reads
the information transmitted by them. The RFID reader converts
the radio waves from the tag into a form that can be passed along to an
information system. Readers that must
scan multiple items, moving quickly on a high-speed conveyor or through a dock
door are more expensive than the basic hand held readers.
Antenna
RFID tag readers use an
antenna to communicate to the RFID tag through the tag’s antenna. Some readers
have integral antenna while other can have various types and sizes of antenna
fitted to them. The antenna is a critical component in the RFID system, as it
has to be built for the coverage area. The antennas vary depending upon the
facility location, size, area, and volume. Usually, an antenna operates in the
3-15 MHz range.
Benefits of RFID in Supply Chain
ü Substantial
productivity gains
ü Elimination of re-labelling costs and effort.
ü Greater
accuracy
ü Flexibility
of data on the tag – e.g., goods and containers can be identified and tracked
using the same tag
ü Ability
to write additional or replacement information to a tag at any stage in the
supply chain.
RFID Vs Barcodes
RFID has several advantages
over conventional barcodes as follows
Ø Barcode can be read only the “line of sight “
RFID tags need to be within the reader’s radio
reach
Ø Barcode cannot
be read inside other containers
RFID tags can be read through most
materials
Ø Barcode provide only limited information
RFID provides unlimited information
Ø Barcode identify classes of products
RFID identify individual products
Falling prices of tags and
readers and the rapid strides in the standards development process is making
RFID technology an increasingly viable option for pallet and case level tagging.
However, the migration of supply chains from barcodes to RFID will require
significant investments and will not happen overnight.
