Safe and Simple Software Cost Analysis Barry Boehm, USC There are a number of simple software cost analysis methods, but they may not always be safe. The simplest is to base your cost estimate on the typical costs or productivity rates of your previous projects. This will work well if your new project doesn’t have any cost-critical differences from your previous projects. But it won’t be safe if some critical cost-driver has changed for the worse. Simple history-based software cost analysis methods would be safer if you could identify which cost driver factors were likely to cause critical cost differences, and if you could estimate how much cost difference it would make if a critical cost driver changes by a given degree. In this column, I’ll provide a safe and simple method for doing this by using the recently-published cost estimating relationships in the book Software Cost Estimation with COCOMO II (by Barry Boehm, Chris Abts, A. Winsor Brown, Sunita Chulani, Bradford Clark, Ellis Horowitz, Ray Madachy, Don Reifer, and Bert Steece, Prentice Hall, 2000). COCOMO II is an updated and recalibrated version of the Constructive Cost Model (COCOMO) originally published in Software Engineering Economics (by Barry Boehm, Prentice Hall, 1981). I’ll also show how the COCOMO II cost drivers can be used to perform cost sensitivity and tradeoff analyses, and discuss how similar methods can be used with other software cost estimation models.