Scientists build to learn; Engineers learn to build.

Even the best planning is not so omniscient as to get it right the first time.

The critical thing about the design process is to identify your scarcest resource. Despite what you may think, that very often is not money. For example, in a NASA moon shot, money is abundant but lightness is scarce; every ounce of weight requires tons of material below. On the design of a beach vacation home, the limitation may be your ocean-front footage. You have to make sure your whole team understands what scarce resource you're optimizing.

A scientist builds in order to learn; an engineer learns in order to build.

System debugging, like astronomy, has always been done chiefly at night.

It is very difficult to make a vigorous, plausible, and job-risking defense of an estimate that is derived by no quantitative method, supported by little data, and certified chiefly by the hunches of the managers

The Waterfall Model is wrong and harmful; we must outgrow it.