
270 ◾ Software Metrics
EXAMPLE 6.23
Suppose A is a set of verication and validation techniques used on a soft-
ware project. We can dene a criterion that maps A to the set of real numbers
by dening g as follows: For each element a of A,
g(a) = the total effort in person-months devoted to using technique a
This measure gives us information about experience with each element of
A. Alternatively, we can dene another criterion, g′, to be a mapping to the
set of nonnegative integers, so that we can compare the effectiveness of two
techniques:
g′(a) = the total number of faults discovered when using technique a
We can also have criteria th