Decision Table Testing
A technique using tables to map combinations of inputs (conditions) to expected outputs (actions).
Full definition
Decision table testing is a black-box technique for testing systems where the output depends on combinations of input conditions. It's especially useful for business rules with multiple interacting conditions.
A decision table has:
- Conditions: Input variables (rows at top)
- Actions: Expected outputs (rows at bottom)
- Rules: Columns showing specific combinations
Example — Loan approval: | | Rule 1 | Rule 2 | Rule 3 | Rule 4 | |---|---|---|---|---| | Credit > 700 | Y | Y | N | N | | Income > 50K | Y | N | Y | N | | Approved | Y | Y | N | N | | Interest Rate | Low | Medium | - | - |
This technique ensures all meaningful combinations are tested. For n binary conditions, there are 2^n possible combinations — decision tables help you identify which combinations matter and reduce test cases systematically.
Decision tables are especially valuable for insurance, finance, and any domain with complex business rules.