In a guest article for the Harvard Business Review, Tim Brown states that Edison implemented Design Thinking while inventing the light bulb.

Tim Brown also states that implementing design during the end stages of development cycle is a tactical use of design and at best "and results in limited value creation" compared to strategically implementing design at the earlier stages of development where design thinking processes can generate the most value.

Link to the original article's excerpt:

http://hbr.org/2008/06/design-thinking/ar/1