Unlike the white-box testing method, the black-box testing is verification in the absence of any knowledge of the software internal organization. The basis for its performing is the external monitoring of the product functionality.

Thus, if a tester does not have any documentation or specifications on system and has no access to the internal code, then the black-box testing becomes the only possible way to ensure correct operation of a software product.

This type of testing has several subtypes: functional testing, non-functional testing and regression testing. Verification can consist of the system functions’, ease of use and scalability check; at the end all mistakes found by testers and corrected by developers are verified.

But any kind of testing, in addition to its advantages, has also some drawbacks, as none of them can cover absolutely every aspect of the system. Black box testingis not an exception.

Unsatisfactory Features of Black-Box Testing:

• Most often, testers have to act randomly in the absence of the project configuration.
• For the same reason there are difficulties in writing test cases.
• Most important elements may happen to be not tested and, accordingly, many bugs can be overlooked.
• There exists a high probability that the cause of the bug found would not be established.

No matter how simple the black box testing method seems to be at first glance, sometimes it cannot guarantee the one hundred percent of quality during the software testing process. Therefore it is necessary to recommend customer black box testing and white box testing as a unit – it will greatly enhance the chances of success.