Henry Petroski: A failed structure provides a counterexample to a hypo...

The most amazing achievement of the computer software industry is its continuing cancellation of the steady and staggering gains made by the computer hardware industry.

Henry Petroski

achievement gains technology

Engineers are not superhuman. They make mistakes in their assumptions, in their calculations, in their conclusions. That they make mistakes is forgivable; that they catch them is imperative. Thus it is the essence of modern engineering not only to be able to check one's own work but also to have one's work checked and to be able to check the work of others.

Henry Petroski

engineering essence mistake

No one wants to learn from mistakes, but we cannot learn enough from successes to go beyond the state of the art.

Henry Petroski

mistake success art

Engineering, like poetry, is an attempt to approach perfection. And engineers, like poets, are seldom completely satisfied with their creations. They notice, even if no one else does, the world that is not quite le mot juste, or the hairline crack that blemishes the structure.

Henry Petroski

engineering perfection doe

The 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 Petroski

purpose simple names

Engineering is achieving function while avoiding failure.

Henry Petroski

engineering function achieve

Failure is Central to engineering. Every single calculation that an engineer makes is a failure calculation.

Henry Petroski

calculations engineering engineers

I 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

engineering criteria numbers

There's so much written about the Titanic, and it's hard to separate what's fact and what's fiction. My understanding is that the way the Titanic was designed, the emphasis was placed on surviving a head-on collision.

Henry Petroski

understanding way fiction

The bookshelf, like the book, has become an integral part of civilization as we know it, its presence in a home practically defining what it means to be civilized, educated, and refined.

Henry Petroski

home mean book

Form follows failure.

Henry Petroski

form

Design is nothing if not decision making.

Henry Petroski

decision-making design decision

What is commonly overlooked in using the computer is the fact that the central goal of design is still to obviate failure, and thus it is critical to identify exactly how a structure may fail. The computer cannot do this by itself . . .

Henry Petroski

engineering design goal

Case 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 Petroski

design-process vocabulary study

All conventional wisdom has an element of truth to it, but good design requires more than an element of truth - it requires an ensemble of correct assumptions and valid calculations.

Henry Petroski

ensemble elements design

Any design, whether its for a ship or an airplane, must be done in anticipation of potential failures.

Henry Petroski

airplane design done

Whether or not science can be applied to that mental construct [i.e. the designed entity] is a matter of availability. If there is body of scientific knowledge that can be applied, then it would be foolish not to exploit it. However, if there is none, it does not mean that the thing cannot be designed, made, and used safely.

Henry Petroski

availability doe mean

Our expectations for a technology rise with its advancement.

Henry Petroski

advancement technology expectations

The Book of the Heart provides a fresh perspective on the influence of the book as artifact on our language and culture. Reading this book broadens our appreciation of the relationship between things and ideas.

Henry Petroski

reading appreciation book

Once a design is completed, subsequent modifications tend to be suggested and approved without the full care that went into the original design. This has happened time and again in bridges and other engineering structures.

Henry Petroski

us

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.