4.1Why Classical Techniques Still Matter

Boundary-value analysis (BVA) and equivalence partitioning (EP) are among the oldest formal test design techniques, dating back to the 1970s. They remain foundational because they address a universal truth: bugs cluster at boundaries. Off-by-one errors, inclusive-vs-exclusive range mistakes, and type coercion edge cases account for a disproportionate share of production defects.

What has changed is the speed at which you can apply these techniques. Manually identifying all partitions and boundary values for a complex API with 15 input fields takes hours. With AI, it takes minutes -- and the AI is less likely to forget an edge case.