Principles of Software testing

Seven Principles of Software testing-


1. Testing shows the presence of bugs.


2. Exhaustive testing is impossible. Unless the software under test has a very small logic, it is not possible to test all the combinations of input values(Permutations and Combinations)


3. Early testing: The testing should be started at an early stage so that enough time is available for testing.


4. Defect Clustering: It is seen that most of the bugs in a software are found in a small number of modules .i.e. 80% of the bugs are found in 20% of the modules.


5. The pesticide paradox: If we keep running the same set of tests over and over again, chances are that no new defects will be discovered by those test cases s the regression test has to keep changing too to accommodate the change in software. Test cases need to be regularly revised and reviewed.


6. Testing is context dependent: The amount of testing done depends on the criticality of the product. i.e. a critical product requires more rigorous testing.


7. Absence of errors fallacy: If no defect is found in software, it does not mean that the software is perfect and ready to be shipped.