Software Testing Principal
- 1. Software Testing Principles 1.Testing shows the presence of Errors: Testing an application can only disclose one or more defects exist in the application. however ,testing alone cannot prove that the application is error free. It is important to design effective test case which find as many defects as possible. 2.Exhaustive testing is impossible: Unless the application under test has very simple logical structure and limited input, it is not possible to test all possible combination of data and scenarios. for this reason, risk and priorities are used to concentrate on the most important aspect to test.
- 2. 3) Early testing: In the software development life cycle testing activities should start as early as possible and should be focused on defined objectives 4) Defect clustering: A small number of modules contains most of the defects discovered during pre-release testing or shows the most operational failures. 5) Pesticide paradox: If the same kinds of tests are repeated again and again, eventually the same set of test cases will no longer be able to find any new bugs.
- 3. To overcome this “Pesticide Paradox”, it is really very important to review the test cases regularly and new and different tests need to be written to exercise different parts of the software or system to potentially find more defects. 6) Testing is context dependent: Testing is basically context dependent. Different kinds of sites are tested differently. For example, safety – critical software is tested differently from an e-commerce site. 7) Absence – of – errors fallacy: If the system built is unusable and does not fulfil the user’s needs and expectations then finding and fixing defects does not help.
- 4. Testing Fundamentals Primary Goal 1.Error Detection 2.Debugging 3.Verification and Validation 4.Test Coverage 5.Quality and Reliability 1.Error Detection : An Error is a human action producing an incorrect result. When programmer makes errors ,they bring in fault to program code. It involve identified bug/errors/defect in software without correcting it.
- 5. 2. Debugging : Debugging occurs as a consequence of successful testing. When testing detect an error, debugging is an action that result in finding the cause of failure and removing it. 3.Verification: Verification is a process of confirming whether software meets its specification. Verification is the assurance that the product of a particular phase in the development Process are consistent with the requirement of that phase.It is low level activity. In simple term , verification makes sure that the “product is