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.

Let’s 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 station.

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 progress.

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 total system.

Where do I use RFID?