Architecture Decision Records

An architecture decision record, usually shortened to ADR, is a short document that records one significant technical decision: the situation that required it, the choice that was made, and what follows from that choice. Each record is numbered, kept with the code it concerns, and never deleted. When a later decision replaces it, the old record stays and is marked as replaced.

The software architect Michael Nygard proposed the format in an article called "Documenting Architecture Decisions