Since testing is a process aimed at detecting defects, a good test can be defined as the one that is most likely to find defects. In order to design a test that has a high probability of detecting defects, a testing specialist should use a constructive destruction approach to examining a given software product. “Constructive destruction” means identifying and eliminating problems in a software product under test.
The complexity of the procedure lies in the fact that it is not the task of the testing specialist to identify the circumstances under which the software product works; on the contrary, the tester tries to detect situations in which the product does not work. When designing a test case, it is important not to make any assumptions that a particular function of the software product is working correctly. You should not expect that any version of the program code will be installed correctly, or that the database structure corresponds to the project, or that the program will automatically recover after a power failure. It also cannot be expected that if the program successfully runs on a given platform, it will work just as well on a computer with less memory space or under the control of another operating system.
If you are having problems with your development process then it is time to resort to QA testing services so that to ensure successful release of your project.
Another characteristic of a well-designed test is its repeatability. If the test fails, it is very important to reproduce the exact conditions under which this failure has happened. For this reason, it is important that the initial state of the system be determined by the test case in terms of the software version used, the hardware configuration, the number of system users, and so on. It is also important that there is a known exact technique used to detect malfunctions. Ideally, the exact sequence of keystrokes, mouse clicks or other events that lead to marked deviations from the expected results should be recorded. In practice, all these details may remain unknown, perhaps because the testing technique is not written in full detail, or because an uncontrolled random event has occurred without the knowledge of the testers. That’s why, when a failure occurs, it is important, without regretting time, immediately reproduce the fault, at that detailing all the actions that led to the malfunction, unless they are explicitly described in the test procedure.