A boundary value is a value on the edge of an equivalence partition. Boundary value analysis is all about testing the component at the boundaries.
For example: Consider the same example that is considered for equivalence partitioning.
There is an Age field that should accept a range of values from 0 to 100 only. For this the boundaries would be 0 and 100. Testing at the boundary would yield 3 data values at each end that should be used for testing. So for 0 the boundary the values would be -1, 0 and 1 (It is to have a value less than the boundary value, the boundary value and the next value) and the values for next boundary 100 are 99, 100 and 101
All the 6 values have to be used to test Age field.
For example: Consider the same example that is considered for equivalence partitioning.
There is an Age field that should accept a range of values from 0 to 100 only. For this the boundaries would be 0 and 100. Testing at the boundary would yield 3 data values at each end that should be used for testing. So for 0 the boundary the values would be -1, 0 and 1 (It is to have a value less than the boundary value, the boundary value and the next value) and the values for next boundary 100 are 99, 100 and 101
All the 6 values have to be used to test Age field.