It is a fact that software testing is time and resources consuming. Testing the software can be observed from different perspectives. It can be divided based on what we are testing. For example, each deliverable in the project, like the requirements, design, code, documents, user interface, etc., should be tested. Moreover, we may test the code based on the user and functional requirements or specifications, i.e., black-box testing. At this level, we are testing the code as a black box to ensure that all services expected from the program exist, work as expected, and with no problem. We may also need to test the structure of the code, i.e., white box testing. Testing can also be divided based on the sub-stages or activities in testing, for instance, test case generation and design, test case execution and verification building of the testing database, etc. Testing ensures that the developed software is, ultimately, error-free. However, no process can guarantee that the developed software is 100% error-free.

Though manual testing is often responsible for missed bugs, sub-optimal test coverage, and human errors, it is impossible to completely replace it with automation testing, even in large projects. Testing such as UX, usability, exploratory, etc., requires human factors because an automatic tool can’t mimic user behavior. Automated testing doesn’t work for security testing, either. Automated vulnerability scanning requires a subsequent manual check because it provides many false positives.