DEXPI 2.0 native exchange and conformance

Start with the DEXPI Engineering Guide when deciding whether the recipient needs the native Plant/P&ID model, native Process/PFD/BFD model, or a Proteus-compatible exchange.

DEXPI 2.0.0 was released on 10 October 2025. It combines the Plant/P&ID and Process/PFD/BFD information models and introduces DEXPI XML as their common serialization. Native DEXPI XML has a Model root containing Import, Object, Components, Data, and References elements; it is not Proteus XML with a different namespace.

NeqSim provides two fail-closed native exporters:

API	Official model imports	Exchange purpose
Dexpi20XmlWriter	Core 2.0.0 + Plant 2.0.0	P&ID plant items, piping, instruments, safeguards, boundaries, and diagram representations
Dexpi20ProcessModelWriter	Core 2.0.0 + Process 2.0.0	PFD/BFD process steps, material ports, streams, and physical state quantities

The official DEXPI XML V2.0.0 XSD is bundled under CC BY 4.0 for deterministic offline validation. Dexpi20ConformanceAssessment verifies its reviewed SHA-256 fingerprint before using the result as conformance evidence.

Process-model export

File exchange = new File("gas-processing-pfd.dexpi.xml");
Dexpi20ConformanceAssessment.Report report =
    Dexpi20ProcessModelWriter.writeAndAssess(process, exchange);
if (!report.isSchemaAndProfileConformant()) {
  throw new IllegalStateException(report.getErrors().toString());
}
Files.write(Paths.get("gas-processing-pfd.conformance.json"),
    report.toJson().getBytes(StandardCharsets.UTF_8));

Each process connection has a dedicated source and target MaterialPort. The ports and Process.Stream carry reciprocal references, stable identifiers, nominal directions, and explicit mass-flow, absolute-pressure, and temperature quantities when finite simulation values are available. The exporter uses kilogram/hour, bar absolute, and degree Celsius references from the official Core physical-quantity model.

Reviewed NeqSim-to-DEXPI Process mappings are:

NeqSim equipment	DEXPI 2.0 Process type
feed or boundary Stream	Source
unconsumed product outlet	Sink
compressor	Compressing
pump	Pumping
separator	SeparatingByGravity
distillation column	Distilling
cooler	Cooling
heat exchanger	ExchangingThermalEnergy
heater	HeatingInFurnace
tank	StoringFluids
control valve	RegulatingFlow
mixer	MixingSimple
splitter	SplittingMaterial
expander	TransportingFluids
pipeline or pipe segment	TransportingFluids

An unmapped equipment class aborts export with its Java type and tag. The exporter never substitutes an unreviewed generic DEXPI type merely to make a file validate.

Conformance layers

Dexpi20ConformanceAssessment records separate decisions for:

1. the bundled official V2.0.0 schema fingerprint;
2. DEXPI XML schema validation;
3. exact versioned Core plus Plant or Process imports;
4. unique identities and resolvable references;
5. NeqSim-supported Plant or Process semantic-profile rules; and
6. the SHA-256 digest and object/reference counts of the assessed file.

Only a report with all five technical gates passing returns isSchemaAndProfileConformant() == true. A Plant file assessed as a Process profile, a version-mixed model import, dangling reference, missing required port/stream relationship, or unknown generated profile type fails explicitly.

The report deliberately states NOT_A_DEXPI_EV_CERTIFICATE and namedCaeRoundTripStatus=QUALIFICATION_REQUIRED. Schema and supported-profile conformance do not replace import/export/reimport testing in the exact CAE product and version used by a project. Record that separate evidence through DexpiToolQualificationRunner and DexpiToolQualificationEvidence.

Release and review controls

• Pin exchange evidence to DEXPI 2.0.0 model URIs and the file digest; never silently reinterpret a later DEXPI model release as 2.0.0.
• Store the conformance JSON, source model revision, generated XML, named-tool round-trip, and accountable semantic-difference review together.
• Compare the committed native golden fixture and semantic inventory when modifying type mappings, topology, units, or serialization order.
• Treat graphics, project standard-library restrictions, vendor extensions, and CAE certification as separate qualification scopes.

Official references: DEXPI Specification 2.0.0 and the DEXPI specification source, licensed CC BY 4.0.