Service Modeling Standards Extend Reach of XML Family

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SML, SML-IF Enable Validation of Sets of Documents

Testimonials -- 12 May 2009 -- Today W3C announces new standards that make it possible to use XML tools to improve the quality of increasingly sophisticated systems and services built from the XML family of standards. Now developers can validate sets of XML documents, either in place, using Service Modeling Language 1.1 (SML), or as a package, using SML Interchange Format 1.1 (SML-IF). Validity constraints are expressed using a flexible combination of XML Schema and ISO Schematron, extended for cross-document use.

"These standards reduce integration costs, while preserving vendor neutrality and providing new flexibility for managing sets of linked XML documents," said John Arwe, Chair of the Service Modeling Language Working Group, which produced the new standards.

SML, SML-IF Enable Validation of Sets of XML Documents

To illustrate what SML adds to the XML ecosystem, consider what happens when someone purchases an airline ticket. Suppose the reservation information is stored as an XML document that includes passenger information. The reservation also refers to a second XML document that stores departure time and other information about the flight. One department manages customer information, another manages flight information. Before any transaction with the customer, the airline wants to ensure that the system as a whole is valid. SML allows the airline to verify that certain constraints are satisfied across the reservation and flight data. This makes it easier to manage inconsistencies, and to do so without writing custom code. As a result, the airline lowers the cost of managing tasks such as informing passengers when flight times change.

An organization may also find that it needs to apply additional constraints when using data in a particular context, for example because of local laws. Developers can use SML to layer on context-specific constraints without duplicating content.

Flexibility Helps Address Social Realities

A number of social situations make clear why organizations choose to manage data in smaller pieces, while not wanting to lose the power of schema validation. The same airline also exchanges information with several car rental partners. Rather than build custom applications for sharing information, the airline can use SML-IF to lower the cost of collaboration. SML extends schema processing to "follow links" to provide assurances that linked-to data has the expected structure. SML and SML-IF can be used with any XML vocabulary, and build on existing standards such XML Schema and ISO Schematron.

SML and SML-IF were developed by the Service Modeling Language Working Group which included the following W3C Members: CA, HP, IBM Corporation, and Microsoft Corporation.

About the World Wide Web Consortium (W3C)

The World Wide Web Consortium (W3C) is an international consortium where Member organizations, a full-time staff, and the public work together to develop Web standards and guidelines designed to ensure long-term growth for the Web. Over 400 organizations are Members of the Consortium. W3C is jointly run by the MIT Computer Science and Artificial Intelligence Laboratory (MIT CSAIL) in the USA, the European Research Consortium for Informatics and Mathematics (ERCIM) headquartered in France and Keio University in Japan, and has seventeen outreach offices worldwide. For more information see


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Testimonials for SML, SML-IF Recommendations

CA | IBM | Microsoft


CA is proud to have helped develop a new standard for modeling that will help improve IT management, security, and governance for customers. With the SML extensions, modelers are able to use XML and XML Schema to model the relationships and constraints in their IT environments.

— Paul Lipton, vice president of Industry Standards and Open Source, CA


IBM is pleased to work with the W3C and its partners to expand the capabilities of XML to include the interchange of sets of linked documents. Our customers want the flexibility to link and validate content across multiple related XML documents. These standards will ensure that they can do this for XML documents that are created and managed with a variety of systems and tools.

— Karla Norsworthy, Vice President, IBM Software Standards


Microsoft Corporation is pleased to see Service Modeling Language 1.1 become a W3C Recommendation. We are committed to enabling interchange of models for services and systems. SML significantly helps reduce complexity and enhances solution interoperability. We congratulate W3C on achieving this important milestone toward an open standard for model interchange.

— Megan Wallent, General Manager, Microsoft Corporation

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