Tuesday, June 12, 2012

Automated Store Replenishment – Volume XXIV


(Continued from previous page)

Two items wrapped together to make a single product is not as common as it used to be, because retailers learned the hard way, in many cases, the clerk can never figure out which of the three barcodes to scan.

Occasionally, suppliers will use part of the UPC code to create a VIN. For example, some cola vendors strip off the first and last digits and use the middle ten digits to identify the product. Some vendors just make up one that is not a valid UPC code at all. This is a common occurrence with shippers. Trapping all the possible errors is a nightmare, and it has taken us years to figure out how to catch them all. Still, we get a new situation every now and again.

We worked with one vendor that striped the check digit off the UPC (the last number), and used it to signify the pack size using their own cryptic system. For example, a valid UPC for a single Snickers candy bar is ‘040000001027’. The carton the Snickers come in is something entirely different, but the vendor would change the check digit of the single bar to ‘1’ to signify a carton, ending up with ‘040000001021’ which is not a valid UPC at all. Of course, if the check digit on the product was already a ‘1’, they would chose a different number. We can always strip off the check digit and generate a valid one, but how they ever kept things straight always amused me.

I’ve even had suppliers try to convince me that the first and last digits are superfluous information. They obviously have never tried to use a scanner to identify a product. If you’ve ever been in a check-out line at the grocery store and the clerk had to scan and item four or five times before the system accepted it, it was usually because the scanner read the check digit incorrectly and they had to scrape the ice off the ice cream container to get it to scan properly.

Some items arrive in stores with a UPC number that eludes all efforts of figuring what they meant to put there. In this case, we resort to calling the supplier and obtaining the correct information. European/Asian 13-digit UPC’s occasionally get into a store. For a time, the accepted solution to convert a 13-digit UPC to 12 digits was simply to ignore the first digit altogether. This method stopped working when ‘0’ was not the first digit, because the absence of the first digit (being non-zero) made the check digit invalid. In America, products with 13-digit barcodes are seldom re-ordered, because they will generally outlive the store. Up until European and Asian markets decided to expand the UPC to 13 digits, they were reserved as ISBN numbers for books, but because it is no longer possible to convert 12 digit UPCs to 13 digits, we may have to learn to live with it.

The first digit of twelve-digit American bar codes were originally meant to denote packaging and is often referred to as the ‘preamble’, but that position has been hi-jacked by manufacturers and now they are just part of the other digits. The last (12th)  digit is the ‘check digit’, and determined by running the first eleven numbers through a computer algorithm. If any of the first eleven digits are changed, the check digit will change. The 2nd through the 6th digit are reserved for the manufacture’s code. Referring to our example above, for Snickers ‘040000001027’, ‘0’ is the preamble, ‘400000’ is reserved for the Mars Candy Company, the next five numbers ‘00102’ signifies Snickers and the last digit ‘7’ is the check digit. Manufacturers may change UPC codes permanently or temporarily without notice. The usual reason is to track items sold by geographical areas. To us, we have no alternative but treat it as a brand new item. As of today, we have recorded 40,652 unique UPCs in our system.

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