Boundary value analysis is a methodology for
designing test cases that concentrates software testing effort on cases
near the limits of valid ranges Boundary value analysis is a method
which refines equivalence partitioning. Boundary value analysis
generates test cases that highlight errors better than equivalence
partitioning.
The trick is to concentrate software testing efforts at
the extreme ends of the equivalence classes. At those points
when input values change from valid to invalid errors are most
likely to occur. As well, boundary value analysis broadens the
portions of the business requirement document used to generate tests.
Unlike equivalence partitioning, it takes into account the output
specifications when deriving test cases.
