What I’ve always felt that a team of people doing something they really believe in is like, is like when I was a young kid, there was a widowed man that lived up the street. He was in his 80’s, and a little scary looking, and I got to know him a little bit — I think he paid me to cut his lawn or something — and one day he told me, “come into my garage, I want to show you something.”
And he pulled out this dusty old rock tumbler. It was a motor and a coffee can and a band between them. And he said “come out here with me,” so we went out to the back and we got some rocks, just some regular old ugly rocks and we put them in the can with a little bit of liquid and a little bit of grit powder, and he turned the motor on and said “come back tomorrow,” as the tumbler was turning and making a racket.
So I came back the next day and what we took out were these amazingly beautiful and polished rocks. The same common stones that had gone in — through rubbing against each other, creating a little bit of friction, creating a little bit of noise — had come out as these beautiful polished rocks.
And that’s always been my metaphor for a team working really hard on something they’re passionate about. It’s that through the team, through that group of incredibly talented people bumping up against each other, having arguments, having fights sometimes, making some noise, and working together, they polish each other, and they polish their ideas. And what comes out are these really beautiful stones.
The series of photos of the 1959 model ends or stops with the photograph in which Kiesler triumphantly shows us the shell of his house like the remains of a creature taken from the seabed, a kind of Moby Dick harpooned and finally captured after the obsessive pursuit of a project that has taken up ten years of the life of the architect.
"I think that everybody has only one basic creative idea and no matter how he is driven off, you will find that he always comes back to it until he has a chance to prove it in purity, or die with the idea unrealized." — Frederick Kiesler
The most serious model shortcoming is that the designer often has a vague, incompletely specified goal, or primary objective. In such cases, the hardest part of design is deciding what to design.
I came to realize that the most useful service I was performing for my client was helping him decide what he really wanted.
Today, we recognize that rapid prototyping is an essential tool for formulating precise requirements. Not only is the design process iterative; the design-goal-setting process is itself iterative. Knowing complete product requirements up front is a quite rare exception, not the norm. Therefore, goal iteration must be considered an inherent part of the design process.
The Goodness Function Cannot be Evaluated Incrementally
The Rational Model assumes that design involves a search of the decision tree, and that at every node, one can evaluate the goodness function of several downward branches. In fact, one cannot in general do this without exploring all the downward branches to all their leaves, which is possible in principle, but leads to a combinatorial explosion of alternatives in practice.
The explicit listing of known constraints in the design program helps here. The designer can periodically scan the list, asking, “Can this constraint now be removed because the world has changed? Can it be entirely circumvented by working outside the design space?”
Perhaps the most devastating critique of the Rational Model, although perhaps the hardest to prove, is that most experienced designers just don’t work that way.
“Conventional wisdom about problem-solving seems often to be contradicted by the behavior of expert designers. Empirical studies of design activity have frequently found ‘intuitive’ features of design ability to be the most effective and relevant to the intrinsic nature of design. Some aspects of design theory, however, have tried to develop counter-intuitive models and prescriptions for design behavior.” — Nigel Cross
Why all this fuss about the process model? Does the model we and others use to think about our design process really affect our designing itself? I believe it does. I believe our inadequate model and following it slavishly lead to fat, cumbersome, over-features products and also to schedule, budget, and performance disasters.
The Rational Model, in any of its forms, leads us to demand up-front statements of design requirements. It leads us to believe that such can be formulated. It leads us to make contracts with one another on the basis of enshrined ignorance. A more realistic process model would make design work more efficient, obviating many arguments with clients and much rework.
The Waterfall Model is wrong and harmful; we must outgrow it.