Traceability links between software specification requirements are evidentially enriched. A traceability link indicates that a second specification requirement is dependent to some degree on a first specification requirement. A likelihood that the second specification requirement for software changes due to the first specification requirement for the software changing, and/or a degree of change of the second specification requirement due to the first specification requirement changing, are determined. A coupling value for the traceability link may be determined as directly proportional to the likelihood that the second specification requirement changes due to the first specification requirement changing, and to the degree of change of the second specification requirement due to the first specification requirement changing.