Let’s see, What is Blackbox Testing? Black box testing treats the system as a “black-box”, so it doesn’t explicitly use Knowledge of the internal structure or code. Or in other words, the Test engineer need not know the internal working of the “Black box” or application.
The main focus in black box testing is on the functionality of the system as a whole. Black box testing is also called behavioral testing testing
ISTQB Definition: Black box testing: Testing, either functional or non-functional, without reference to the internal structure of the component or system.
Blackbox testing types
- Equivalence partitioning
- Boundary value analysis
- Decision tables
- State transition testing
We will discuss these techniques in details.
Black Box Testing – Steps
- Initially, requirements and specifications of the system are examined.
- Tester chooses valid inputs (positive test scenario) to check whether SUT processes them correctly. Also, some invalid inputs (negative test scenario) are chosen to verify that the SUT is able to detect them.
- Tester determines expected outputs for all those inputs.
- The test cases are executed.
- Software tester compares the actual outputs with the expected outputs.
Advantage of Blackbox Testing
The tester can be non-technical.
Used to verify contradictions in actual system and the specifications.
Test cases can be designed as soon as the functional specifications are complete
Disadvantage of Blackbox Testing
The test inputs need to be from large sample space.
It is difficult to identify all possible inputs in limited testing time. So writing test cases is slow and difficult
Chances of having unidentified paths during this testing