To check that every requirements link in your model has a valid target in a requirements document, navigate to Analysis > Requirements Traceability > Check Consistency and run the Model Advisor checks:
To execute these checks from the Model Advisor, navigate to By Product > Simulink Requirements > Requirements Consistency.
When modeling for high-integrity systems, to check that model elements link to requirement documents, run these high-integrity checks:
For DO-178C/DO-331, see Check for blocks that do not link to requirements
For IEC 61508, IEC 62304, EN 50128, and ISO 26262, see Check for model objects that do not link to requirements