An architectural marvel when it opened 11 years ago, the new Denver International Airport’s high-tech jewel was to be its automated baggage handler. It would autonomously route luggage around 26 miles of conveyors for rapid, seamless delivery to planes and passengers. But software problems dogged the system, delaying the airport’s opening by 16 months and adding hundreds of millions of dollars in cost overruns. Despite years of tweaking, it never ran reliably. Last summer airport managers finally pulled the plug–reverting to traditional manually loaded baggage carts and tugs with human drivers. The mechanized handler’s designer, BAE Automated Systems, was liquidated, and United Airlines, its principal user, slipped into bankruptcy, in part because of the mess.
Such massive failures occur because crucial design flaws are discovered too late. Only after programmers began building the code–the instructions a computer uses to execute a program–do they discover the inadequacy of their designs. Now a new generation of software design tools is emerging. Their analysis engines are similar in principle to tools that engineers increasingly use to check computer hardware designs.