test-design-techniques

Boundary value analysis focuses testing on input edges where bugs occur most frequently. Identify the valid range limits (e.g., 1–100 for quantity), then generate test cases at and just outside those boundaries: values like 0, 1, 2, 99, 100, and 101 to catch off-by-one errors and edge-case handling failures.

Equivalence partitioning groups inputs that behave identically, reducing redundant test cases across similar ranges. Boundary value analysis targets specific edge points within those groups where defects cluster. Together, they minimize test volume while maximizing coverage of distinct behaviors and failure modes.

Pairwise testing ensures every pair of parameter values is tested together at least once, dramatically cutting combinations compared to exhaustive testing. For multi-parameter scenarios, it maintains high interaction coverage while eliminating redundant permutations, delivering faster test execution and bug detection.

Decision tables map business rules with multiple conditions to expected outcomes, making them ideal for rule-heavy logic with interdependent inputs. Use them for workflows with conditional branches, pricing rules, or approval logic where you need to verify all condition combinations systematically.

Boundary value analysis applies to any ordered or ranged input: numeric fields, date ranges, string lengths, and list sizes. For strings, test minimum length (empty, single character) and maximum length boundaries; for dates, test year/month/day limits to catch validation and formatting bugs.

State-transition testing maps allowed state changes and validates transitions systematically. Pairwise testing reduces redundancy when multiple parameters influence state behavior. Together, they ensure stateful workflows handle parameter interactions correctly without exhaustive test explosion.