Testing rules with several conditions.
WHAT A DECISION TABLE IS
A grid of conditions and the resulting actions.
WHAT IT PROVIDES
Systematic coverage of combinations, and revelation of gaps.
WHEN TO USE ONE
Business rules depending on several conditions.
WHAT IT REVEALS
Combinations the specification never addressed.
WHY THAT MATTERS
Unaddressed combinations become whatever the code happens to do.
WHAT COMBINATORIAL EXPLOSION MEANS
Conditions multiplying until testing every combination is impossible.
WHAT TEN BINARY CONDITIONS PRODUCE
Over a thousand combinations.
WHAT PAIRWISE TESTING DOES
Covers every pair of values across a small set of tests.
WHY THAT IS SUFFICIENT FREQUENTLY
Most defects involve one or two factors, not many interacting.
WHAT TOOLS PROVIDE
Generation of minimal sets covering all pairs.
WHAT TO ADD BEYOND PAIRS
Combinations known to be risky Combinations occurring commonly in practice
WHAT STATE TRANSITION TESTING COVERS
Systems with modes, and the transitions between them.
WHAT TO TEST
Every valid transition Every invalid transition attempted Every state's behaviour
WHY INVALID TRANSITIONS MATTER
They are where undefined behaviour lives.