H. James Harrington & Christopher F. Voehl 
Making the Case for Change [PDF ebook] 
Using Effective Business Cases to Minimize Project and Innovation Failures

The best time to stop projects or programs that will not be successful is before they are ever started. Research has shown that the focused use of realistic business case analysis on proposed initiatives could enable your organization to reduce the amount of project waste and churn (rework) by up to 40 percent, potentially avoiding millions of doll