In software testing, what is boundary value analysis?

• A. Testing at the edge of input ranges to find off-by-one errors and boundary problems.
• B. Testing only the happy path.
• C. Testing the performance under maximum load.
• D. Testing for memory leaks.

Answer: (A)

Boundary value analysis focuses on testing input values at the edges of the allowed range and at points just inside or outside those edges. The idea is to expose off-by-one errors and other boundary problems that often hide when testing only typical or middle-range inputs. If the valid input is between 1 and 100, you’d check values at and around the boundaries—such as 1, 2, 99, 100, and values just outside like 0 and 101, plus a middle value like 50. This ensures the system handles boundary conditions correctly rather than assuming near-edge inputs behave the same as mid-range inputs. The other options describe different testing goals (happy path, performance under load, memory leaks) that aren’t about boundary behavior.