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UDEF provides a path to semantics integration,
complements ebXML Core Components
Ron Schuldt
While ebXML Core Components and various content standards organizations continue their efforts to address the complex syntax issues of message design and assembly, the Universal Data Element Framework (UDEF) offers a complementary approach for addressing basic semantics integration issues
The Universal Data Element Framework is a rules-based naming convention with unlimited semantics flexibility and richness that conforms to ISO/IEC 11179 (the same standard that ebXML Core Components adopted) and provides a structured ID that can be used as an alignment mechanism across the various XML standards and the back-office systems that interface with each other.
Since the UDEF complements the ebXML Core Components Technical Specification and is focused on semantics integration, if used in conjunction with Core Components, it offers a ready-made library of core component artifacts. Figure 1highlights the terminology (names within the bubbles) defined and used within ISO/IEC 11179 and the focus of the UDEF on data element concepts, where the semantics are established, compared to that of ebXML Core Components that also addresses the representation.
Figure 1. UDEF, Core Components share ISO/IEC 11179 terminology
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UDEF structured IDs provide the key mechanism to support semantics integration
For a given data element concept defined in ISO/IEC 11179-1, the UDEF structured ID provides an alias that computers could use as an indexing mechanism between systems and standards. In the same fashion that the Internet uses structured IDs for IP addresses to avoid collisions, the UDEF IDs would provide a similar means to avoid semantics collisions between systems. The Electronics Industry Data Exchange (EIDX) Cross Reference (XRef) project provides a good example of a mapping matrix across several ebusiness standards used within the electronics industry that are tied together by UDEF names and the associated structured IDs.
Figure 2 highlights extracts from the UDEF tree structures and how a UDEF structured ID is derived from an object tree and a property tree for the data element concept - purchase order document type code.
Figure 2. UDEF tree structures expressed in purchase order document type code
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UDEF IDs can help reduce the costs of building interfaces between systems
With support from a Web service that can generate a gap analysis report between any two XML files that have UDEF IDs embedded, the design-time effort required to align any two back-office systems or between trading partners can be significantly reduced. A UDEF based gap analysis Web service proof-of-concept was successfully demonstrated at the August 2003 CompTIA Breakaway Conference in San Diego. The demonstration showed that UDEF IDs could be independently mapped to a sample purchase order in RosettaNet and a sample purchase order in xCBL.
The resultant gap analysis report highlighted the points of intersection as well as the basic differences in message structure design between the two XML formats. Figure 3 highlights the cost reduction opportunities that could be possible if all systems provided UDEF IDs at the APIs. Since most system interfaces today are built using a point-to-point approach, the UDEF ID canonical alternative could provide an attractive cost reduction opportunity - especially when a given system must interface with three or more other systems.
Figure 3. Potential cost savings with UDEF IDs
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UDEF trees could provide a ready-made library of Core Components artifacts
Since UDEF names are not artificially constrained in length, UDEF trees offer a semantically rich library of ISO/IEC 11179 compliant building blocks that could become a source for populating ebXML's Core Components library. The entire set of UDEF trees have been converted to XML to enable applications to embed the UDEF IDs within their APIs.
Since the UDEF property terms map directly to the "Permissible Representation Words" specified in paragraph 8.3 of the Core Components Technical Specification, the UDEF trees for the property words provide a ready-made library of Core Component types and supplementary components. Figure 4 highlights the one-for-one comparison.
Figure 4. CCTS Representations and UDEF property words
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Figure 5 provides a few examples of ebXML Core Component types and supplementary components within UDEF property trees.
Figure 5. UDEF property tree
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Similarly, each UDEF object tree provides a ready-made library of ebXML Core Component object class qualifiers and associations. Figure 6 provides a few examples of qualifiers and associations (role and type) for the UDEF "Enterprise" object.
Figure 6. Examples of Core Component object class qualifiers and associations
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UDEF ID could permanently replace the Temporary Identifier suggested by the Core Components Technical Specification (CCTS)
Paragraph 5.3.1 Step 6 within the Core Components Technical Specification version 2.01 states "Assign a Temporary Identifier to the new item in the form of a 6 digit alphanumeric string, chosen at the discretion of the user." Since the temporary nature of the identifier implies that it is simply a placeholder and that the permanent identifier solution has not been fully addressed by the Core Components team, the UDEF ID would offer a permanent solution.
To make UDEF real requires a global registry for UDEF tree structures
The aerospace and defense industry is in the process of identifying a suitable global host for UDEF tree structures. The selected suitable host will be responsible for managing and extending the tree structures as well as providing training and promoting UDEF on a global scale. Figure 7 provides a summary view of the overall concept of operation. Once the global host is announced a UDEF pilot will be conducted to demonstrate its value in helping organizations reduce the costs of interfacing systems.
Figure 7. UDEF concept of operation
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Since many organizations (especially large businesses and government organizations) have the need to maintain multiple back-office systems and their interfaces, those same organizations could leverage UDEF IDs within mapping matrices. UDEF IDs could provide a structured indexing mechanism to the data within their own systems as well as to their trading partners' systems.
The Association For Enterprise Integration (AFEI) created UDEF and the organization offers UDEF for adoption as an open standard for e-business and XML interoperability. The Aerospace Industries Association is working to expand UDEF as the naming convention solution to XML interoperability between standards.
About the author
Ron Schuldt is a Senior Staff Systems Architect within the Systems Design and Integration organization of Lockheed Martin Enterprise Information Systems. Currently, he is Co-Lead of the Aerospace Industry Association's Business Interoperability Framework Working Group responsible for defining the e-business data standards for the aerospace industry.
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