Debugging represents half of development costs

Research Finding:
Debugging and associated rework takes about 50% of the time spent in a typical software development cycle.

Sources:

Cover of Software Productivity Software Productivity
Cover of IEEE Computer Improving Software Productivity
Cover of American Programmer Swords and Plowshares: The Rework Cycle of Defense and Commercial Software Development
Cover of Fast Company They Write the Right Stuff
Cover of IEEE Software Software Process Improvement at Raytheon
Cover of Software Inspection: An Industry Best Practice Software Inspection: An Industry Best Practice
Cover of Estimating Software Costs Estimating Software Costs
Presentation What We Have Learned About Fighting Defects
Cover of Peer Reviews in Software: A Practical Guide Peer Reviews in Software: A Practical Guide