50 years ago, the barcode was born. Millions of barcodes are read around the world every hour of the day – but how did they come to be?

In 1971, two engineers demonstrated a large, tubular wand reading a 20cm long barcode for the first time, the 11-digit number it represented appearing on the display panel of a plain steel box.

This took place in the London Head Office of Sainsbury’s following months of discussion with a small unit of the Plessey company, who had been behind one of about 60 responses to Sainsbury’s quest for a reliable method of capturing and transmitting data remotely.

Most of the unsuccessful responses were pure science fiction, while many relied upon keyed data in some form or another; the solution from ICL, for example, involved mobile teletype terminals with trailing power cables. I ruled this out along with all keyboard-based solutions - the data collection system needed to be error-free, usable without training, and easily portable.

The realities of retail

Previously, I had successfully developed for Sainsbury’s a system for producing picking lists (the information for the distribution depots to assemble and transport goods to supermarkets). The system was up and running on our ICL 1900 series computer, on which I had installed data transmission systems that allowed head office to send the lists to each depot.

This helped, but Sainsbury’s was at the time not only the biggest supermarket group in the UK but had the highest turnover per square foot of selling space in the world, and they suffered from a problem familiar to all retailers: having too much stock on site ties up capital and space, but having too little results in out-of-stock items. Getting the balance was key, and the current system was not working.

The amount of each product delivered to each store was calculated centrally and weekly, based on previous sales and current stock - the latter having to be counted laboriously by the supermarket staff. The forecast and delivery dates were invariably wrong, and stores were perpetually overstocked on some things and out of stock of others. For years it had been tweaked by experts but the system never was, and never could be, satisfactory. Customers get upset when products are not available, and Sainsbury’s board was very sensitive to customers’ demands. A new system was desperately required.

The hunt for a solution

A high-level committee was formed and I was appointed as the I.T. representative. Despite endless meetings, head-scratching and trips to Europe and the USA, no solutions were found. Eventually a ‘dream solution’ was described. Each product would be allocated a shelf space based on an average two-days sale. At the end of each day, staff would assess how much of each product was required to refill the shelf space.

This information would be processed immediately, and supplies sent out overnight to arrive at the supermarket the next day where staff would move the stock straight from the truck to the shelf. The main advantage would be reducing out-of-stocks, therefore improving Sainsbury’s reputation - but another advantage was there for the taking. Sainsbury’s was so successful that store overcrowding was a common complaint; this system would eliminate the need for a stockroom, creating more selling space.

The logistics required for such a system were challenging to say the least. There was nothing on the market capable of quickly capturing and transmitting to head office several hundred locations’ worth of error-free data. There would immediately be 250,000 item orders per day, and this was planned to increase dramatically. Even an error rate of 0.001% would result in a noticeable number of lost orders.

A new method of data capture

Hence, Sainsbury’s had put out the call to companies and private inventors. There were a number of vocal objectors to the proposed barcode idea - it was new, unproven and the equipment to make it useable didn’t exist. But I saw it immediately as a, if not the, solution, and I had arranged the demonstration as a means of getting the I.T. director on-side. It worked.

The small team I led quickly grew. A basic pilot system was set up to collect data, with supermarket staff calling out the results over telephone to head office, who then input them to the depot picking system. This proved both that the basic idea of calculating orders by evaluating shelf space daily worked, and that it was easy for anyone to assess the requirement with minimal training.

Suddenly shelves could be re-stocked within hours, and the board of directors demanded immediate expansion of the system. At one time we had 16 telephone operators at head office taking down the data from 70 supermarkets, and depot management worked hard to change the established distribution process. In the meantime, we kept searching for our dream data-collection solution.

There had some attempts to develop a functional barcode reading system, but as the 1970s took flight there were still none on the market. The UK Plessey company had developed its own two-bar code design but had found no takers - until Sainsbury’s came along in 1971. Reading tests showed that errors were so few as to be non-measurable. By 1972 the first barcodes were up and running, and over the first several years of operation and millions of barcode readings, we never detected any errors.

Trials and tribulations

The main problem turned out to be power, initially, as there were no small batteries available to do the job; two lead-acid car batteries were used at first, making the portable device a rather clumsy trolley. The NASA space programme soon resulted in smaller batteries which enabled the device to be shrunk into a satchel, and when lithium batteries became available the unit became hand-held.

Plessey had designed the device to transmit data from each supermarket over the standard telephone network. At head office, a receiver dialled the supermarkets’ units automatically each day, collecting the data on a magnetic tape that was transferred to the picking list system. Each transmission took only a couple of minutes. Each supermarket was equipped with two data collection devices and one transmitter - all the staff had to do was plug the devices into the transmitter. As more supermarkets switched over to this system the calling-up operation at head office was also automated, using a front-end processor that auto-dialled the supermarkets.

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The very first supermarket to trial the system was in Islington. Barcodes identified every product place on the shelves, and a part-time shelf filler collected the data without issue. The trial ran for some weeks, producing just one mysterious problem - sometimes part of the order was not transmitted. It was eventually discovered it was caused by static: when the trolley was wheeled close to a cooler cabinet a spark sometimes jumped as the trolley earthed to it, producing a signal erasing all orders recorded to that point. Other problems were caused by human error; once, a cleaner unplugged the transmitter to plug in her vacuum cleaner, meaning the store unit could not communicate with head office. These issues were quickly fixed and the system was an outstanding success: out-of-stocks were virtually eliminated, and stockholdings and labour costs were reduced even more than anticipated.

The beginning of a new era

In August 1972 an article appeared in The JS Journal – the Sainsbury’s house magazine – describing the system that by then had been installed in 30 of the company’s 250 stores, and was rapidly being implemented company-wide. Mr J.D. Sainsbury himself described it as the greatest step forward in the company’s 100 year history.

It took over two years to switch all the supermarkets to the new system, which was gradually expanded to include all product groups as well as the 2000 grocery products. At the time, the impact was huge, resulting in my giving a number of presentations to interested parties - firstly at BCS, then further afield in the UK retail trade, then at international conferences in Amsterdam and Paris.

50 years later, you will still see shelf barcodes in every Sainsbury’s: there are now more than 1,000, identifying up to 10,000 products each. You will also see them – well, almost everywhere else.

This is an abridged version of the full article The Birth of the Barcode by Derrick Brown, which appeared originally in the Spring 2023 issue of Resurrection, the journal of the Computer Conservation Society. This article was written with thanks to the Sainsbury Archive for providing image licenses and access.

Derrick Brown is also the author of An Unexpected Development with Austin Macauley publishers.

A CCS seminar on this matter was given in January 2023. This article is also scheduled to appear in a forthcoming edition of ITNOW.