Code coverage is a measure used in software testing. It describes the degree to which the source code of a computer program|program has been tested.
Code coverage was among the first methods invented for systematic software testing. The first published reference was by Miller and Maloney in Communications of the ACM in 1963.
Code coverage is one consideration in the safety certification of avionics equipment. The guidelines by which avionics gear is certified by the Federal Aviation Administration (FAA) is documented in DO-178B and the recently released DO-178C.