How safety engineers test everyday products to destruction

In 1967, a Canadian pediatrician named Henry Bray spent a full decade running public education campaigns telling parents to keep medicine bottles out of children’s reach. The campaigns failed. Kids kept getting poisoned. So Bray changed tack: instead of trying to change human behavior, he set an engineering challenge. The result, the push-down-and-twist childproof cap, is now so ordinary that most people never think about the thinking behind it. That cap is a neat entry point into the unseen world of test engineering — the people who figure out not just whether a product works, but whether it survives the real world, including the humans who use it.

Tech journalist Alex Davies, author of How to Keep a Plane in the Sky: Tales from the Wild, Unseen World of Test Engineering, argues that test engineers are the unsung heroes of the technological age. While founders and inventors get the glory, test engineers take an idea and turn it into something you can buy with reasonable assurance that it won’t hurt you. Their work follows a five-step process: observe and imagine what could happen to the product; set standards for what it must survive; create a test that mimics real-world conditions; make sure the test is workable (repeatable, practical, and controllable); then judge whether the product met the standard.

Factor of safety and the limits of strength