Black Box Testing

So What is Black Box Testing ?

Black box testing is a software testing techniques in which
functionality of the software under test (SUT) is tested without looking at the internal code structure, implementation details and knowledge of internal paths of the software.This type of testing is based entirely on the software requirements and specifications .

In Black Box Testing we just focus on inputs and output of the software system without bothering about internal knowledge of the software program.  

                         

The above Black Box can be any software system you want to test. For example : an operating system like Windows, a website like Google ,a database like Oracle or even your own custom application. Under Black Box Testing , you can test these applications by just focusing on the inputs and outputs without knowing their internal code implementation.

Types of Black Box Testing

There are many types of Black Box Testing but following are the prominent ones -

• Functional Testing - This black box testing type is related to functional requirements of a system; it is done by software testers.
• Non - Functional Testing - This type of black box testing is not related to testing of a specific functionality , but non-functional requirements  such as performance, scalability, usability.
• Regression Testing - Regression testing is done  after code fixes , upgrades or any other system maintenance to check the new code has not affected the existing code.

Black box testing strategy:

Following are the prominent test strategy among-st the many used in Black box Testing

• Equivalence Class Testing: It is used to minimize the number of possible test cases to an optimum level while maintains reasonable test coverage.
• Boundary Value Testing: Boundary value testing is focused on the values at boundaries. This technique determines whether a certain range of values are acceptable by the system or not.It is very useful in reducing the number of test cases. It is mostly suitable for the systems where input is within certain ranges.
• Decision Table Testing: A decision table puts causes and their effects in a matrix. There is unique combination in each column.