Software Testing

Patriot Missile Defense System, 1991

nter the following equation int

The goal of a software tester is to find bugs, find them as early as possible, and make sure they get fixed.

Forget about Murphy and think Philip Crosby. He was correct when he declared that quality really is free. It's just a matter of the software development team following a process, taking their time, being disciplined, and attempting to do it right the first time.

A quality assurance or test group that reports to executive management has the most independence, the most authority, and the most responsibility.

If the goal of software QA is to prevent bugs, you could argue that performing static testing on the product spec, design documents, and code (Chapters 4, "Examining the Specification," and 6, "Examining the Code") is a type of software QA because you're preventing bugs from occurring. Bugs found this way never make it through to later be found by the testers testing the finished software.

You may be wondering, if software testing alone can't guarantee a product's quality, what a Software QA group would do to achieve it. The answer is having nearly full control over the project, instituting standards and methodologies, carefully and methodically monitoring and evaluating the software development process, feeding back solutions to the process problems they find, performing the testing (or overseeing it), and having the authority to decide when the product is ready to release. It may be an oversimplification to say that it's like having a project manager who's primary goal is "no bugs" as opposed to keeping the product on schedule or under budget, but it's a pretty good description.

Chapter 3, "The Realities of Software Testing," cited the following definition of a person in this role:

A Software Quality Assurance person's main responsibility is to examine and measure the current software development process and find ways to improve it with a goal of preventing bugs from ever occurring.

Quality can't be tested in. Period.

Being a software tester and working under this charter has a unique and very important characteristic: You aren't responsible for the quality of the software! This may sound strange, but it's true. You didn't put the bugs in the software, you had your project manager and the programmers review and approve your test plan, you executed your plan to the letter and despite all that effort, the software still had bugs. It's not your fault!