Chapter 5

Tip #24 

Invest an appropriate amount of effort assessing the size of the software that will be built. The size of the software is the single most significant contributor to project effort and schedule.

Tip #25 

Don't assume that effort scales up linearly as project size does. Effort scales up exponentially.

Tip #26 

Use software estimation tools to compute the impact of diseconomies of scale.

Tip #27 

If you've completed previous projects that are about the same size as the project you're estimating—defined as being within a factor of 3 from largest to smallest—you can safely use a ratio-based estimating approach, such as lines of code per staff month, to estimate your new project.

Tip #28 

Factor the kind of software you develop into your estimate. The kind of software you're developing is the second-most significant contributor to project effort and schedule.