In boundary value analysis/testing, we only test the exact boundaries rather than hitting in the middle. For example: If there is a bank application where you can withdraw a maximum of 25000 and a minimum of 100. So in boundary value testing we only test above the max and below the max. This covers all scenarios.

The following figure shows the boundary value testing for the above-discussed bank application.TC1 and TC2 are sufficient to test all conditions for the bank. TC3 and TC4 are duplicate/redundant test cases which do not add any value to the testing. So by applying proper boundary value fundamentals, we can avoid duplicate test cases, which do not add value to the testing.