Overview
ISO/TS 20625:2002 provides rules for generating W3C XML Schema files (XSD) from EDI Message Implementation Guidelines (MIGs), primarily UN/EDIFACT MIGs. The Technical Specification defines a repeatable method to represent EDI semantic facts in XML so that existing EDI implementations and know‑how can be reused with XML without re‑inventing data models. The document is focused on XSD generation (not DTDs) and is applicable in principle to other EDI standards beyond EDIFACT.
Key Topics and Requirements
- Scope and applicability
- Derivation of XML schemas from EDIFACT MIGs; rules are equally applicable to other EDI standards.
- Does not apply to DTDs.
- Tag naming rules
- Two variants: EDI‑tag based names (preferred for traceability) and “speaking” names (human‑readable), with mandatory documentation of EDI origin (e.g., an EDIPath attribute).
- Typical prefixes: M_ (message), G_ (segment group), S_ (segment), C_ (composite), D_ (data element).
- Structure mapping
- XML schema structure must be compatible with MIG structure (segments, segment groups, composites, data elements).
- EDI elements map to XML elements; identical EDI tags produce aggregated XML elements unless disambiguation is required.
- Semantic fidelity
- Emphasis on representing semantic facts accurately and keeping XML messages as lean as possible.
- Schema constraints and multiplicity
- Use of XSD constructs (sequence, minOccurs/maxOccurs, element refs) to reflect MIG occurrence rules.
- Documentation and traceability
- Inclusion of MIG technical information (names, qualifiers, code lists) in schema annotations or attributes.
- References
- Normative references include ISO 8601 (dates/times) and ISO 9735‑1 (EDIFACT syntax rules).
Applications and Who Should Use It
- Integration architects and EDI specialists converting EDIFACT messages to XML for application integration.
- XML/XSD authors and schema generation tool developers who need deterministic rules to create XSDs from MIGs.
- Software vendors and implementers bridging legacy EDI systems with web services, XML APIs, or middleware.
- SMEs seeking to reuse EDI investments while adopting XML for document exchange and validation.
Practical Benefits
- Preserves EDI semantic integrity while enabling XML validation and tooling.
- Facilitates interoperability between EDI and XML ecosystems and reduces re‑engineering costs.
- Improves traceability from XML elements back to original EDI constructs for governance and testing.
Related Standards
- UN/EDIFACT Message Implementation Guidelines (MIGs)
- ISO 8601 (date/time representation)
- ISO 9735‑1 (EDIFACT application syntax rules)
- W3C XML/XSD recommendations
Keywords: ISO/TS 20625:2002, EDIFACT, EDI to XML, XSD generation, MIG, Message Implementation Guideline, XML schema, EDIPath, schema mapping.
Open preview (PDF)Electronic data interchange for administration, commerce and transport (EDIFACT) — Rules for generation of XML scheme files (XSD) on the basis of EDI(FACT) implementation guidelines
