Federal agencies have started also looking for private sector standards, as well as vendor offerings to build their systems, and the adoption of these standards by Federal agencies can encourage the overall growth of standards. At the XML 2001 conference in December 2001, put on by IDEAlliance, Dr. Robert Cherinka of MITRE Corporation, a not-for-profit research center that often works for Federal agencies, discussed the use of emerging Web services standards in the Department of Defense (DoD).
Web services are software components accessed or invoked by other software, accessed over the Web, and based largely on XML, a new high-powered language that enables the exchange of structured data and processes over networks. Web services include:
-- Simple Object Access Protocol (SOAP) that provides a format for messages
-- Universal Description, Discovery and Integration (UDDI) that specifies directories to find services available over the Web
-- Web Services Description Language (WSDL) that offers a uniform language for detailing these components
Cherinka showed how a large bureaucracy such as DoD can use Web services like SOAP, WSDL, and UDDI. With Web services, end-user commands, agencies, or line operations can match information needs to resources without the extended time and potential errors of manual searches. An important benefit of Web services is the linking of needs and offerings, in a process called brokering. Mediated brokering establishes automated connections between parties, while distributed brokering allows for collections or interconnections of brokering services.
Cherinka described how the orchestration of Web services uses a process called workflow, which will vary from one organization to another. Workflows are tasks that follow specified routes or interactions according to an agreed-upon set of rules. For example, a paired exchange between a purchase order and a response acknowledging receipt and agreeing to its terms is a simple form of workflow. Because Web services are loosely coupled components, they can accommodate different workflows, yet still allow for interoperability between components and among collections of Web services. One of the ways to assemble these services in a working configuration is presented in the Electronic Business XML or ebXML specifications, approved in May 2001.
The DoD, according to Cherinka, established a Message Text Format, a collection of over 300 standard messages based on XML (XML-MTF) that gives DoD a common language for objects related to military doctrine and terminology. XML-MTF will give DoD a language for messages using the Web services infrastructure. DoD has approved XML-MTF for use its own use and NATO in 2002.
