No design, no matter how common or seemingly insignificant, is without its adamant critics as well as its ardent admirers.

We can't simply blame the engineers when things go wrong because, no matter how well they plan, things don't always go according to plan.

Successful design is not the achievement of perfection but the minimization and accommodation of imperfection.

Design is nothing if not decision making.

I employ case studies of failure into my courses, emphasizing that they teach us much more than studies of success. It is not that success stories cannot serve as models of good design or as exemplars of creative engineering. They can do that, but they cannot teach us how close to failure they are.

We call the fates of the Titanic and the Concordia - as well as those of the space shuttles Challenger and Columbia - 'accidents.' Foreseeing such undesirable events is what engineers are expected to do. However, design trade-offs leave technological systems open to failings once predicted, but later forgotten.