Supermarket Self Service Checkout

Self-service checkouts have been steadily rising in number since British supermarket giant Tesco introduced the technology in the UK in 2010, with the aim of making paying for groceries much more efficient.

From less than 100,000 terminals throughout the world back in 2008 to nearly half a million installed today, they have gone through many changes in this short period, vastly improving in speed and accuracy.

Self-service checkouts come in many shapes and sizes, depending on the floor space available, but usually consist of four main sections: the barcode scanner, touchscreen display, bagging area and the payment terminal.

Barcode scanners feature a wipe-friendly surface and see-through panel over which items are passed to be logged. Beneath this panel are components that illuminate, scan, convert and then decode the barcode, swiftly passing data

back and forth between the till and its host computer or data centre. Items that can’t be barcoded (for example, loose fruit and veg) can be selected manually via a touchscreen display.

Loose items must also be weighed using a pressure pad that matches the item against its expected weight. If this does not happen, the customer and supervisor are both alerted with the now-familiar “unexpected item in the bagging area’ warning. Otherwise, it’s simply a matter of paying, using a combination of debit/credit card reader, note reader and coin counter to check and verify the payment.

Despite improvements in accuracy and speed, the advantages of self-checkouts are debated. Certainly, one operator monitoring up to six tills means lower staff costs. However, for some consumers human interaction is a vital part of the shopping experience and, in busy periods, you can end up waiting longer than normal if the machine has a fault.

Black and white all over

Barcodes were first developed in the US in the late-Forties, but achieved acceptance with the Universal Product Code (UPC) introduced in 1974 for Wrigley’s chewing gum. The UK version (known as UPC-A) consists of a strip of black bars and white spaces above a sequence of 12 numbers, the first six defining the manufacturer, five for the product and a final check digit to ensure the code has been scanned correctly. The bars and spaces are merely a machine-friendly representation of the readable UPC number, designed so it can be illuminated, scanned and checked by the till at high speed.

Once the sale is concluded, barcode data is used in a number of different ways, from controlling stock levels to updating loyalty points and creating a profile of each customer’s shopping habits for future marketing. Barcodes have not just made shopping quicker and easier but also helped cement supermarkets’ dominance over the last few decades.

Stand and deliver?

Supermarkets know only too well the threats self-service checkouts pose, not just from committed fraudsters (who have been known to use counterfeit barcode stickers) but otherwise ‘honest’ customers, tempted by the control they now have over what used to be handled by a real person. However, there are significant security safeguards in each of the key areas of weighing, bagging and paying, as well as constant monitoring by both human and CCTV eyes, to prevent theft.

When an error is detected (for instance, an item scanned but not bagged), there are both audible and visual warnings to alert both the customer and supervisor. Despite this, research suggests up to a third of all customers have stolen items at self-service tills, using anything from tampering with the scales to bagging without scanning, or simply walking off without paying. Retailers are understandably cagey about revealing exactly how many customers get away with it though.