Interview Questions

Would like to know whether Black Box testing techniques like Boundary Value Analysis and Equivalence Partitioning - during which phases of testing are they used,if possible with examples ?

Software QA/Testing Technical FAQs


(Continued from previous question...)

Would like to know whether Black Box testing techniques like Boundary Value Analysis and Equivalence Partitioning - during which phases of testing are they used,if possible with examples ?


Answer1:
Also Boundary Value Analysis and Equivalence Partitioning can be used in unit or component testing, and generally is used in system testing
Example, you have a module designed to work out the tax to be paid:
An employee has £4000 of salary tax free. The next £1500 is taxed at 10%
The next £28000 is taxed at 22%
Any further amount is taxed at 40%

You must define test cases that exercise valid and invalid equivalence classes:
Any value lower than 4000 is tax free
Any value between 4000 and 5500 must paid 10%
Any value between 5501 and 33500 must paid 22%
Any value bigger than 33500 must paid 40%
And the boundary values are: 4000, 4001, 5501, 33501


Answer2:
This Boundary value analysis and Equivalence partitioning is used to prepare the positive and negative type test cases.
Equivalence partitioning: If you want to validate the text box which accepts the value between 2000 to 10000 , then the test case input is partitioned as the following way
1. <=2000
2. >=2000 and <=10000
3. >10000
The boundary Values analysis is checking the input values on boundaries. IN the above case it can checked with whether the input values is on the boundary or above the boundary or in low boundary.

(Continued on next question...)

Other Interview Questions