But can’t bar codes do everything I want?
A common question heard here, followed by
"RFID is so expensive". As with most questions there are two
answers for both of these statements. The use of bar code is
something we have become very familiar with, and it is difficult
to find an application that has not benefited from the use of
bar code. However, bar codes do have some very important
limitations that RFID can overcome. Using the two hand in hand
can give some significant benefits to a system. The second
question is a difficult one to answer, but in many questions the
answer is "how can you afford to NOT implement RFID".
Let me explain further. Two areas that bar codes do not perform
well at are: changing data and harsh environments. Let’s face
it, a bar code does not stand up to an automobile paint show
very well (there are of course always exceptions). And once you
have printed a bar code, that’s it. You can always print a new
one, but you cannot change the first one.
RFID tags have the capability to have the data changed on them
many times depending on the specific type. You can store
information and update it as a tag moves through a process,
keeping the important information with the tag (and the item)
and so making it available at any point in its life. Now some
items do not need information changed frequently and this may
well be an example of when a bar code will do the job needed.
consider an operation where an item is moved through a
series of processes along a "conveyer belt" system. At each
station, the item is taken off the belt and an operation is
performed on the item. It is then returned to the belt to
move on to the next station. The item has a bar code on it,
and at each station the bar code is read as it enters the
station and again as it leaves. The work done is recorded on
the central database system. The operator has to move the
item to the reader (or the reader to the item) twice at each
Now let’s think about an RFID system in this situation. The
items all have a tag attached instead of a bar code label.
The reader is setup to cover the access to the belt, such
that the operator must remove the item through the readers
window when it is removed and replaced. Because the reader
is able to sense the tag in any orientation, it is not
necessary for the operator to swivel the item to get a good
read. As the item is replaced on the belt, the tag is
updated with the latest information about the work in
Think about the time savings alone when the operator does
not have to manipulate the item to a scanner. Think about
the benefits of using a portable reader to interrogate the
work in progress at any time.
Now think about the item being used in a harsh environment.
The same tag will work in most situations, hot, cold, dirty
etc. where a standard bar code label might have problems
(direct thermal printed labels don’t like the heat too much)
and so give the flexibility needed to incorporate into a
Where do I use RFID?