ReqIF (Requirements Interchange Format)
ReqIF (Requirements Interchange Format) is an XML-based exchange format for requirements, standardised by the OMG. It carries not just the plain requirement text, but also attributes, data types, document structure (spec hierarchies) and links between requirements (spec relations) — the same building blocks that make up requirements traceability.
What is ReqIF needed for?
ReqIF grew out of a very concrete problem in the automotive industry: OEMs and suppliers often work with different requirements-management tools, yet need to exchange requirements together with their context — not as a PDF or Excel export, but machine-readable and with the structure preserved. ReqIF solves this in a vendor-neutral way: instead of a proprietary interface between two specific tools, a ReqIF export on one side and a ReqIF import on the other is enough.
What is inside a ReqIF file?
The standard defines several building blocks:
| Building block | Meaning |
|---|---|
| Specification | A requirements document as a hierarchical tree of Spec Hierarchies |
| Specification Types | Types define which attributes objects, relations, and specifications carry |
| Spec Object | A single requirement with its attribute values |
| Spec Relation | A directed link between two Spec Objects — the basis for traceability |
| Spec Hierarchy | A node in the document structure of a Specification |
This structure makes ReqIF more powerful than a plain table export: attribute definitions and links travel along, not just the free text.
The practical limitation
The standard defines what ReqIF can transport — not what a specific tool actually supports. Similar to model exchange via XMI between SysML tools, a ReqIF round trip between two vendors is often lossy in practice: custom attribute types, link types or formatting are not interpreted identically by every tool. Before relying on ReqIF as a continuous exchange path, it is worth running a concrete test with the tools involved — not just checking the feature sheet.
How ReqIF fits into a continuous, auditable traceability chain across tool boundaries is described on our page Requirements Traceability.