The traceability matrix enables you to determine the extent of relationships between requirements and other requirements and between requirements and tests. It helps you verify that all requirements are met and identify changes to the scope of your requirements when they occur.
The traceability matrix lists source requirements and their associated requirements and tests. The total number of relationships is listed for each source requirement. A low value may imply that the source requirement is not associated with enough requirements or tests. A high value may imply that the source requirement is too complex and can perhaps be simplified. A zero value indicates that no relationship exists.
For task details, see How to Use the Traceability Matrix.