Original subtitles

- Hi, I'm William Lidwell

and this is Universal Principles of Design.

In this movie, iteration,

how the long way can be the short way.

In 1959, the industrialist Henry Kremer

created a series of challenges and rewards

centered on human-powered flight.

It was basically the XPRIZE of its day.

The first Kremer prize offered

50,000 pounds for the first

human-powered plane to fly

a figure eight around two markers

one half mile apart.

The challenge was formidable.

Dozens of teams tried and failed

for more than 17 years,

each spending months designing

and building their planes

just to have them crash

minutes after a test flight.

Enter the aeronautical engineer Paul MacCready.

MacCready knew that the big P problem

was not making a human-powered plane

but speeding up the design-build-test cycle

to learn how to make a human-powered plane,

replacing theory and conjecture

with real-world testing.

By focusing on designing a plane

that could be rebuilt in hours versus months,

MacCready enabled his team

to dramatically speed up iteration,

which correspondingly sped up their learning.

Six months later, MacCready's

Gossamer Condor flew over 2,000 meters,

claiming the first Kremer prize.

MacCready approached this problem

assuming that a lot of failed prototypes

are going to be required to solve the problem.

And so he focused on getting through them

as fast as possible.

The phrase "fail fast, fail often"

is based on this philosophy.

Contrast this with a more traditional approach

of spending a lot of time up front

doing analysis, planning, and design

to build the perfect beast

and then expecting it to work the first time out.

Even people who intellectually know

the perils of this approach often fall into the trap.

So what is iteration in the context of design?

Iteration is defined as repeating a set of design,

development, and test operations,

with each repetition building on the last,

until the desired result is achieved.

Now this is not a clean, linear process.

Good iteration involves a lot of experiments

that don't work, dead ends that take time to explore,

and invariably a good many failures.

But failure in an iterative paradigm is not the end.

It's just another iteration from which you learn.

I often liken design iterations to rungs

on a ladder of understanding.

No great heights can be achieved

without climbing a lot of them.

A fundamental lesson of iteration

relates to another principle of design

referred to as Gall's Law.

Gall's Law states that all complex systems

that work evolved from simpler systems that worked.

The implication is that if you're designing

a complex system, a physical product,

a software application, a business process,

whatever, you should start by designing

and building a simple system first,

learn what works and what doesn't,

and then improve it iteratively over time.

This seems like the long way of doing things

to the uninitiated, but trying to shortcut

this process is futile.

It will take longer, cost more,

and have a higher probability of terminal failure.

So whether you use iteration to develop

great products and services,

invent the next killer app,

or win the next Kremer prize,

there are still two prizes unclaimed, by the way.

Remember, the long way is the short way to get there.