If you haven't read the remarkable cover by Jena McGregor in BW called "Eureka, We Failed! How Smart Companies Learn From Their Flops," get to it now. It's all about the role of failure in innovation.
One of the best books on the subject is "Success Through Failure," by Henry Petroski. Here's a quote from his book that I find most compelling. He's talking about "the inventors, the engineers, the designers of the world who are forever trying to improve it through the things in it. To these intrepid pioneers of purpose, a failure of any kind is not such much a disappointment as an opportunity. The tweak the things we know to turn them into things we did not even know that we needed."
Petroski goes on to say "And the single most common characteristic of such creative people is the way in which they view failure. They recognize that a failure not only provides them the opportunity to carry out the process of design and development anew but also enables them to conceive of something new and improved to obviate the triggering failure."
This is a way of looking at the world that is very difficult in the buttoned-down world of business which is used to driving out all failure, all defects. That is why introducing an innovation culture into a Six-Sigma process control culture is so hard and problematic. But still necessary.