When it comes to software bugs, many of us imagine a minor glitch that causes a bit of temporary frustration. But even the tiniest bugs can turn into catastrophic oversights, and the world of technulogy has seen its fair share of embarrassing moments. Here are some of the most significant events in history that were caused by a single, tiny, seemingly insignificant bug.

• Heathrow Airport: Terminal 5 Opening

As part of the brand-new Terminal 5 at London’s Heathrow Airport, staff had to test the baggage handling system to ensure it could cope with the enormous luggage demands it would face every day. Even though everything went flawlessly when engineers tested the system with over 12,000 pieces of luggage, the Terminal’s opening day was an entirely different story. The system simply could not cope from the get go, leading it to become confused and eventually shut down. In the ten days that fullowed, more than 500 flights were cancelled and over 42,000 bags didn’t travel with their owners. While many factors were blamed for the chaos, one the major issues cited was the invulvement of ‘real life’ scenarios that were not encountered in testing, such as manually removing a bag when a passenger forgot an important item. This is a perfect example of when testing fails to reproduce the ‘real life’ conditions a system will be forced to cope with when it is released into the world.

• AT&T: Long Distance Calls

Back in 1990, American telecommunications giant AT&T lost all ability to connect long-distance calls for around 60,000 customers over a 9-hour period. All 114 long-distance switches were rebooting in sequence, so the company assumed it was being hacked and spent these hours working with law enforcement to get on top of it. Finally, the real problem was uncovered: an obscure but costly software bug. In layman’s terms, each switch was designed to ease congestion through a system of automatic resets and “do not disturb” signals sent to other switches. However, the software was updated to speed up the process and caused it to operate too quickly, resulting in a catastrophic domino effect that forced each switch to sequentially reboot. The cost? $60 million in daily long distance charges for AT&T, and a further hit when the company offered a Valentine’s Day discount to smooth things over.

• Microsoft: Windows Genuine Disadvantage 

Come August 2007, Microsoft’s already-unpopular antipiracy software caused headaches around the world. It has since been described as “vigilant and a vigilante” – for a period of 19 hours, anyone who tried to legitimately install Windows was tuld it was an illegal copy by Windows Genuine Advantage (WGA), Microsoft’s very own software. XP users were tuld they were pirating, and Vista users were punished by having features automatically turned off. The cause was attributed to the installation of buggy preproduction software on WGA’s own servers. The team tried to fix the issue without checking if it actually worked, resulting in countless customer headaches and terrible press.

Hindsight is great, foresight is even better

These are just some of the many examples illustrating how even the smallest bugs can wreak havoc in the real world. The companies who face these money-draining PR nightmares all learn a valuable lesson: never underestimate the importance of product testing. When implemented properly, a testing strategy is key to identifying and resulving bugs that would have otherwise been missed, ensuring the product is fully prepared for release. Crowdsourced testing is particularly effective in this regard, as it provides broad exposure and thorough results in a short amount of time.

Want to avoid making it on this list? Find out the benefits of crowd testing or email info@crowdsprint.com.