James Dyson was frustrated with the way vacuum cleaners worked where they used a traditional approach of using suction power to pick up dirt into a bag.
James during one of the visits to industry saw mill found inspiration the way conical cyclone was used to accelerate the air and push it out using centrifugal force. He was convinced using a similar approach he can disrupt the vacuum cleaner market. It took him more than 5200 prototypes before he came up with bagless dual cyclone market.
Another good example where the inspiration for innovation came from a unrelated source.