Barcodes

Few retailers, manufacturers or distributors could run a business today without tracking individual items by computer, whether they be groceries at a supermarket checkout, goods on a production line or parcels at a postal sorting office.

The original – and still the most familiar – tracking device is the machine-readable barcode. Although simple barcodes were introduced in the late 1960s to track rail wagons and factory components, the technology’s breakthrough came in the 1970s when the US supermarket industry decided the time had come to introduce a standardised system for automating checkouts. The initial frontrunner was a ­“bullseye” system proposed by RCA, in which an 11-digit product code was encoded in concentric rings. But trials showed this to be unreliable and the eventual winner was a linear code developed by IBM, with data encoded in the width and spacing of parallel black and white lines read by a laser scanner.

By the 1980s the linear system had been adopted worldwide, with information allocated according to an agreed universal product code (UPC).

From the shopper’s point of view, the most obvious benefit of barcodes is that – when they are working properly – they speed up the checkout process. For retailers, this means they can employ fewer staff at the tills – an accelerating trend now that many chains are encouraging, or forcing, customers to scan their own purchases at a self-service machine.

More important advantages for companies lie in their being able to track and re-order stock, respond quickly to changes in demand and alter prices far faster than is possible with manual pricing systems.

Although the UPC remains the dominant form of barcode, many other codes are in use for more specialised commercial applications, from books and libraries to pharmaceutical packaging.

The familiar linear barcode ­exemplified by the UPC reads across from left to right in one dimension. But the main growth area in labels is now in 2D or matrix codes that can hold much more data; they are printed as a grid with tiny black and white squares that are read both horizontally and vertically.

The most important 2D system is the QR (quick response) code. It was invented for the Japanese car industry but has recently spread rapidly as the de facto standard for labelling objects with ­information and internet links that can be read with mobile phones – laying the foundations for the so-called ­“internet of things”.

At the same time, radio frequency identification (RFID) tags – smart labels that can be read without an optical scanner or camera needing to have a line of sight to the code – are multiplying rapidly in many fields of commerce, supplementing or even replacing barcodes.

Clive Cookson