Understand the two different checks
An IDS audit checks whether the .ids file follows the IDS schema and implementer agreements. An IDS model check evaluates whether applicable IFC objects satisfy the requirements in that valid specification. Run them in that order.
1. Confirm purpose and scope
- State the delivery milestone and responsible discipline.
- Confirm the target IFC schema declared by each specification.
- Use names that a reviewer can understand without opening the XML.
- Separate unrelated requirements so one result does not hide another.
2. Audit the IDS file
Open the file in an IDS audit tool and resolve schema errors before checking any IFC. Look for unsupported beta syntax, missing identifiers, invalid data types, malformed restrictions and values that conflict with their declared type.
3. Review applicability and requirements
| Question | Why it matters |
|---|---|
| Which objects are applicable? | An overly broad entity or classification filter creates irrelevant failures. |
| Is the requirement required, optional or prohibited? | Cardinality changes the meaning of a missing or repeated value. |
| Is the property set and property name exact? | Similar labels do not guarantee the same IFC property. |
| Is the value restriction realistic? | Enumeration, pattern, range and unit choices must match the delivered data. |
| Does the requirement need geometry? | IDS is for alphanumeric information; use another method for geometric clearance or clash rules. |
4. Test known positive and negative cases
Use a tiny IFC fixture or a controlled model containing one object that should pass and one that should fail. If both produce the same result, fix the specification or implementation before running a project-wide check.
- Audit the IDS with zero structural errors.
- Run a known passing IFC object.
- Remove or change the required value and confirm it fails.
- Test an object outside applicability and confirm it is ignored.
- Repeat the test in the intended production checker.
5. Review evidence, not only totals
A dashboard showing 98% compliance may still hide a critical missing classification. Group failures by specification, object class and cause. Save the IDS version, IFC checksum or filename, checker version and timestamp with the result.
Release checklist
- The IDS title, version, author and date are meaningful.
- Every specification has a stable identifier.
- The target IFC version matches the delivery.
- Applicability finds the intended object population.
- Required values have been tested with pass and fail examples.
- Geometry expectations are documented elsewhere.
- The approved IDS file is stored with change history.