Estimating Software Costs, 2nd Edition

Chapter 14Estimating Software Prototypes

Prototyping and requirements gathering are often parallel activities. In some situations such as the Agile development methods, the prototypes may even substitute for other forms of requirements gathering, although this is not often a safe practice.

Among SPR’s clients, prototyping is a very common practice. For projects between about 100 and 5000 function points in size, about 80 percent of them have had some form of prototype development prior to full development. Of the prototypes, about 65 percent were disposable, 10 percent were time box, and 25 percent were evolutionary in nature.

To have an optimal effect, prototypes should serve as a method for augmenting written requirements and written specifications, ...