What is Black Box Testing?

Black box testing is done from the customer's viewpoint. It does not require examining the code of the program, it involves the looking at the specifications of the application and focuses solely on the output.It is also called as Functionality testing or Data driven testing or Behavioural testing.In this type of testing, tester does not have the access to the source code. Based on the SRS document, test data is prepared.The purpose of this testing is to cause failures in order to make faults visible.Another purpose is to assess the overall quality level of the application.

There are various techniques to be used to generate test scenarios for effective Black box testing:-

1. Requirement based testing
2. Positive and negative testing
3. Boundary value analysis
4. Decision tables
5. Equivalence partitioning
6. State based testing
7. Compatibility testing
8. User documentation testing
9. Domain testing
10. Cause effect graphing
11. Error guessing

Advantages of Black box testing:-

• It helps in identifying any incomplete, inconsistent requirement
• Tester test the application in a user point of view
• Tester needs no knowledge of code or its written language in this testing
• Test cases can be designed as soon as the SRS is ready
• It enables verification of the overall functionality of the application
• It puts the system through the valid and invalid forms of user inputs
• It finds the overall quality of the application

Disadvantages of Black box testing:-

• If the specifications are not clear , test cases are hard to design
• May leave many program paths untested
• Exhaustive testing is not possible
• We can find a failure not the root cause in this testing