Software Estimation: Demystifying the Black Art

Chapter 18. Special Issues in Estimating Size

Applicability of Techniques in This Chapter

	Function Points	Dutch Method	GUI Elements
What’s estimated	Size, Features	Size, Features	Size, Features
Size of project	S M L	S M L	S M L
Development stage	Early–Middle	Early	Early
Iterative or sequential	Sequential	Sequential	Sequential
Accuracy possible	High	Low	Low

Once you move from directly estimating effort and schedule to computing them from historical data, size becomes the most difficult quantity to estimate. Iterative projects might use a size estimate to help determine how many features can be delivered within an iteration, but they usually focus on techniques designed to estimate features more directly. Estimation in the later stages of sequential projects tends ...