A requirements model (RQM) helps you analyze any kind of written requirements and link them with users and groups who will implement them and with design objects in other models. You can use an RQM to represent any structured document (e.g. functional specification, test plan, business goals, etc.) and import and export hierarchies of requirements as MS Word documents.
You can link requirements to objects from other types of models, external files, and other requirements on the Requirement Traceability Links tab of the requirement property sheet.
For detailed documentation, see Requirements Modeling.