It’s widely recognized that input values at the extreme ends of the input domain cause more errors in the system. More application errors occur at the boundaries of the input domain.Boundary value analysis (BVA) is based on testing the boundary values of valid and invalid partitions. ‘Boundary Value Analysis’ Testing technique is used to identify errors at boundaries rather than finding those that exist in the center of the input domain.
Boundary Value Analysis is the next part of Equivalence Partitioning for designing test cases where test cases are selected at the edges of the equivalence classes.Boundary value analysis can be applied at all test levels.
Example on Boundary Value Analysis Test Case Design Technique:
Assume, we have to test a field which accepts Age 22 – 58
Minimum boundary value is 22
Maximum boundary value is 58
Valid Inputs: 22,23,57,58
Invalid Inputs: 21 and 59
Test case 1: Enter the value 21 (22-1) = Invalid
Test case 2: Enter the value 22 = Valid
Test case 3: Enter the value 23 (22+1) = Valid
Test case 4: Enter the value 57 (58-1) = Valid
Test case 5: Enter the value 58 = Valid
Test case 6: Enter the value 59 (58+1) =Invalid
Example 2:
Assume we have to test a text field (Name) which accepts the length between 8-14 characters.
Minimum boundary value is 8
Maximum boundary value is 14
Valid text length is 8, 9, 13, 14
Invalid text length is 7, 15
Test case 1: Text length of 7(min-1) = Invalid
Test case 2: Text length of exactly 8 (min) = Valid
Test case 3: Text length of 8 (min+1) = Valid
Test case 4: Text length of 13 (max-1) = Valid
Test case 5: Text length of exactly 14 (max) = Valid
Test case 6: Text length of 15 (max+1) = Invalid