| At the time this book was first
published, in 1979, it was a well-known rule of thumb that in a typical
programming project approximately 50 percent of the elapsed
time and more than 50 percent of the total cost were expended in
testing the program or system being developed.
Today, a quarter of the century later, the same is still true. There
are new development systems, languages with built-in tools, and programmers
who are used to developing more on the fly. But testing
still plays an important part in any software development project.
Given these facts, you might expect that by this time program testing
would have been refined into an exact science. This is far from
true. In fact, less seems to be known about software testing than
about any other aspect of software development. Furthermore, testing
has been an out-of-vogue subject—it was true when this book
was first published and, unfortunately, it is still true today. Today there
are more books and articles about software testing, meaning that, at
least, the topic has more visibility than it did when this book was first
published. But testing remains among the “dark arts” of software
development.
This would be more than enough reason to update this book on
the art of software testing, but there are additional motivations. At
various times, we have heard professors and teaching assistants say,
“Our students graduate and move into industry without any substantial
knowledge of how to go about testing a program. Moreover, we
rarely have any advice to provide in our introductory courses on how
a student should go about testing and debugging his or her exercises.” |
