Glossary » design rationale
the reasoning that leads to design decisions. Documenting design rationale is important for validating that the correct design decision was made, to help those who are trying to interpret ambiguous design decisions or examples that don’t fall clearly within a design principle, and to avoid going back and changing design decisions without knowing the original reasons in the first place. A design rationale can be an important tool in arriving at the initial design decision in the first place. Rationale should give advantages and disadvantages of a choice and include rejected alternatives (so that those alternatives don’t keep popping up for reconsideration).