Dyson's prototyping method for finding a breakthrough empirically across thousands of cyclones.
James Dyson's framework, from Invention, pp. 80 to 102.
Start with a setup
Test one particular configuration of the cyclone.
Change one thing
Make a single change, such as an angle, a diameter or a duct shape, and nothing else.
Test and see
Run the test and see what difference that one change made, so you learn what works and what fails.
Repeat
Keep going through thousands of prototypes, as Brunel did with the ship propeller, until the breakthrough comes.
From chapter: Chapter Five: The Coach House, pp. 80–102
Fired from his first company in 1979, Dyson spends fifteen years in debt building his cyclonic bagless vacuum in the coach house. A full bag clogging the Hoover's pores gave him the idea, and he makes 5,127 prototypes changing one thing at a time, proving the experts wrong about cyclones working at 0.5 microns. Every major manufacturer rejects the design because they protect their bag business, so he licenses it in Britain, Japan, Canada and America, loses a deal to Amway, which then copies it, and sues for five years before settling for $1 million. In 1992 he decides to stop licensing and make the machine himself.