I 100% agree with you. Software is "soft". Making changes to a code base is very cheap. Iteration just makes sense in software even for critical systems. If you build a suboptimal bridge, you have to live with it. If you write suboptimal software, you can test the actual product and fix it before you even ship. You can't really test a bridge outside of simulations. GP's comparison is apples to oranges in a lot of ways.
geezerjay|7 years ago
Just to pick a few nits, actually bridges are indeed tested during and after construction. It used to be standard practice to do test runs with near limit loads to inaugurate bridges, consisting of getting a fleet of military vehicles or water tankers to cross the bridge while surveyors monitored the bridge's response.
Nowadays non-destructive testing techniques are favoured for a number of reasons, including the fact that sensor rigs can also be used throughout the structure's lifetime to help determine its fatigue life.