A failed structure provides a counterexample to a hypothesis and shows us incontrovertibly what cannot be done, while a structure that stands without incident often conceals whatever lessons or caveats it might hold for the next generation of engineers.
Henry PetroskiThe plain wooden toothpick, it may be argued, is among the simplest of manufactured things. It consists of a single part, made of a single material, intended for a single purpose-from which it gets its simple name. It is also among the most convenient and ready of things. It can be used directly out of the box-there being no instructions to read, no parts to assemble, no priming or booting required, and no maintenance expected. When it has served its purpose, it is simply discarded.
Henry PetroskiCase studies of failure should be made a part of the vocabulary of every engineer so that he or she can recall or recite them when something in a new design or design process is suggestive of what went wrong in the case study.
Henry PetroskiI emphasize that virtually every engineering calculation is ultimately a failure calculation, because without a failure criterion against which to measure the calculated result, it is a meaningless number.
Henry Petroski