At a recent computer software engineering course in the US, the participants were given an awkward question to answer: "If you had just boarded an airliner and discovered that your team of programmers had been responsible for the flight control software, how many of you would disembark immediately?"

Among the ensuing forest of raised hands only one man sat motionless. content to stay on board. With his team's software, he reasoned, the plane was unlikely to even taxi as far as the runway, let alone take off.