FOM Validation

Validation checks that an object model is well-formed and standard-compliant before you export it or hand it to an RTI. Catching problems in SimGe is far cheaper than discovering them at federation start-up.

What validation checks

Validation confirms that the generated XML document conforms to the official IEEE 1516 XML schema (.xsd) for the chosen standard and profile.

Standards and schema profiles

Schema validation applies to the two IEEE 1516 standards. For each standard you can validate against any of three schema profiles:

Schema profile	Validates
OMT	The base Object Model Template document.
FDD	The FOM Document Data (the form an RTI consumes).
DIF	The Dependency/Interface document.

Standard	Schema profiles available
IEEE 1516-2010	OMT, FDD, DIF (2010 .xsd files)
IEEE 1516-2025	OMT, FDD, DIF (2025 .xsd files)

HLA 1.3 (FED) is not schema-validated. The legacy .fed format has no XML schema, so the FED viewer offers no Validate action — only copy and export.

Running validation

Validation is performed in the FDD viewer (the FDD Viewer (2010) / FDD Viewer (2025) tab of a module's OME). Two toolbar selectors control it:

1. The standard selector — IEEE 1516-2010 or IEEE 1516-2025 (this also picks which viewer/document you see).
2. The schema selector — DIF, FDD, or OMT.

Click Validate to check the document against the selected standard + schema profile. Changing either selector re-targets validation, so you can verify the same model against several schemas. Validation also runs automatically during import, so problems in a source file are reported as it is read (see Importing & Exporting).

Because SimGe authors models as modules, validation runs against the merged result — the same composition that export and code generation use — so what you validate is what you ship.

Reading the results

Validation results open in a dedicated results window:

• A clean run reports success.
• Problems are listed with enough detail to locate them (the offending element and the rule or schema constraint involved).
• The window is color-coded by outcome so you can tell success from warnings and errors at a glance.

The validation results for an FDD document. The report header records the FILE, KIND (FDD), the SCHEMA it was checked against (here IEEE1516-FDD-2025.xsd, set by the FDD viewer's toolbar selector), and the STATUS (FAILED). Findings are listed below the header, and Copy Details copies the full report to the clipboard.

Work through the listed items, fix them in the OME, and re-validate until the model is clean.

Common issues and fixes

Symptom	Likely cause	Fix
Unresolved dependency warnings	A referenced module is missing or its name does not match.	Add or relink the module; see Managing Modules and Modular FOM Concepts → Dependencies.
Schema errors on export	A field required by the chosen standard is empty or malformed.	Complete the required fields in the relevant OME table, then re-validate.
Datatype / reference errors	An element points at a datatype or parent that no longer exists.	Repoint it in the OME to a valid target.

When to validate

• Before exporting a FOM for an RTI.
• After a large edit or a merge of modules.
• After importing, to confirm the upgraded model is clean.

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