Why do people bother to test their software? Shouldn it have been built so it doesn have any errors?
The main reason software test methods are used is that they are effective in reducing the defect content of software products. People ought to build high-quality software, but to make sure, you have to test the final product. And, programmers aren’t perfect. Testing saves lots of money — some say as much as 100:1 over field-disovered defects. • Why do we need automated tools at all? Because the size and complexity of applications has grown so rapidly, “old style” methods of testing just don’t work any more. In the late 1990s you really don’t have the economic choice any longer NOT to consider test automation — unless you don’t want to test at all! • Can’t we do manual testing like we always did? You can, but you’ll find that it is difficult and costly and not terribly reliable or effective. In fact, if you are dealing with a complicated program at all, you’ll virtually be compelled to do some kind of automated testing. Then, too, there are some kinds of analyses that you simply can’t
