- Testing Axioms
- Software Testing Is a Risk-Based Exercise
- Testing Can't Show That Bugs Don't Exist
- The More Bugs You Find, the More Bugs There Are
- The Pesticide Paradox
- Not All the Bugs You Find Will Be Fixed
- When a Bug's a Bug Is Difficult to Say
- Product Specifications Are Never Final
- Software Testers Aren't the Most Popular Members of a Project Team
- Software Testing Is a Disciplined Technical Profession
- About This Article
Think about this for a moment. You're an exterminator charged with examining a house for bugs. You inspect the house and find evidence of bugsmaybe live bugs, dead bugs, or nests. You can safely say that the house has bugs.
You visit another house. This time you find no evidence of bugs. You look in all the obvious places and see no signs of an infestation. Maybe you find a few dead bugs or old nests but see nothing that tells you that live bugs exist. Can you absolutely, positively state that the house is bug free? Nope. All you can conclude is that in your search you didn't find any live bugs. Unless you completely dismantled the house down to the foundation, you can't be sure that you didn't simply just miss them.
Software testing works exactly as the exterminator does. It can show that bugs exist, but it can't show that bugs don't exist. You can perform your tests, find and report bugs, but at no point can you guarantee that there are no longer any bugs to find. You can only continue your testing and possibly find more.