The Secret of Innovation
This is one of the latest articles by James P. Andrew, Hal Sirkin in the Boston Consulting Group publications. In his article argues that innovation, both at the project and portfolio level, can be managed better by drawing cash curves of cumulative cash flow. The arguments on the article can drive managers to question their assumptions about various kinds of risks (market, financial, technical, etc.) and consider alternative development models.
You can download the article from here