Requirements Traceability Matrix
Also known as: RTM
A Requirements Traceability Matrix (RTM) is a document that maps each requirement to the test cases that verify it, making it possible to confirm every requirement has been tested and every test case exists for a reason. It's the tool teams use to answer "have we tested everything we're supposed to?" with evidence instead of a guess.
An RTM is typically a table: one row per requirement, with columns linking to the test case IDs that cover it. Reading across a row shows every test verifying that requirement; reading down a column shows which requirement a given test case actually justifies existing for.
It earns its keep in two specific situations: regulated industries where auditors need documented proof every requirement was tested, and large projects where it's easy to lose track of coverage gaps — a requirement nobody wrote a test for, or a test case that no longer maps to any real requirement and should probably be retired. Test case management tools (TestRail, Xray, Zephyr) usually generate an RTM automatically from linked requirements and test cases rather than requiring one maintained by hand.
