He concludes that they often fail because the very management practices that have allowed them to become industry leaders also make it extremely difficult for them to develop the disruptive technologies that ultimately steal away their markets. Well-managed companies are excellent at developing the sustaining technologies that improve the performance of their products in the ways that matter to their customers. Disruptive technologies, however, are distinctly different from sustaining technologies.
Disruptive technologies change the value proposition in a market.
When they first appear, they almost always offer lower performance in terms of the attributes that mainstream customers care about. In computer disk drives, for example, disruptive technologies have always had less capacity than the old technologies. They are typically cheaper, smaller, simpler and frequently more convenient to use. Therefore, they open new markets. Further, because with experience and sufficient investment, the developers of disruptive technologies will always improve their products' performance, they eventually are able to take over the older markets.