What good innovators know
Why is constancy so important? Because innovation is not going to be successful as a discrete project. Innovation faces too many hurdles and upsets the status quo far too often. If innovation becomes a discrete effort, bounded with a start and end date, then it will not return the results that were hoped for, since everyone can breathe a sigh of relief when the project's finally done.
As Edison and countless others have demonstrated, you rarely get it right the first time, and if you are stymied by early failure, then you'll never find and implement the best ideas. Innovation, as has been pointed out by individuals with far more to say about it than me, will create some failures. Your job isn't to avoid the failures, since you can't predict them in advance, but to reduce the cost and impact of the inevitable failures. In other words, keep moving.
Another reason constancy is important is that people need to learn how to innovate and learn that it's OK to innovate. The firms we hold up as innovators - P&G, 3M, Apple, Google, Gore and so on all have long track records of innovation. 3M has considered it a core value for over 70 years. One could argue that this is a cultural bias. What I'll say is that anything that gets done repeatedly and successfully over time informs and shapes the culture. So which came first - the constancy or the culture?
Constancy also has something to do with success. Even if there are failures along the way, if a firm sticks to its guns and continues to innovate over time, the processes and techniques will improve and the firm will have increasing success. We all want the home run at the first at bat, but that's rare even for home run hitters. The Hall of Fame is full of people who played many, many years to achieve greatness, and is notably lacking in "flash in the pan" players.
We at OVO like to talk about consistent, sustained innovation processes that become part of the fabric of the organization - a way of life within the business. This, in my mind, is the only way to succeed at innovation.