The adoption of XML as the data description layer in leading enterprise resource planning (ERP) applications may bring a degree of interoperability to typically shuttered ERP systems.
It is also likely to make the work of the Open Applications Group (OAG) standards body more relevant to the industry.
The OAG last month announced the release of updates to its namesake integration specification OAGIS, which defines methods for exchanging data and process information among ERP applications and other business applications from different vendors.
The OAGIS 6.0 update adds support for Extensible Markup Language (XML) as a meta language, addresses supply-chain integration standards, and provides explanatory material for developers. Advanced planning and scheduling APIs are expected within the year.
Although ERP vendors and middleware developers have embraced XML for describing data in their suites, the OAG specification calls for the use of XML in conjunction with the OAG Business Object Document (BOD) model to link disparate applications.
"We're looking to XML to provide the structure of messages going back and forth between applications," said Christopher Kurt, US-based senior associate at PriceWaterhouseCoopers. Kurt, a member of the OAG advisory board, has spearheaded the group's XML efforts.
"The traditional way that most companies approached integration between applications was similar to transferring flat files around," Kurt said. "XML allows us to provide context or hierarchical information."
Without altering their own applications, ERP and other application vendors can leverage third-party XML-based libraries to facilitate cross-application integration and take advantage of new capabilities as they are added to XML, Kurt explained.
The OAG is working with SAP and PeopleSoft, in addition to middleware vendors and others, to push the adoption of the OAGIS and coordinate the XML support, according to David Connelly, president and chief technology officer at OAG.
"We're working very closely with the OAG to help define the BOD," said Jeff Halsaver, open integration strategy leader at PeopleSoft.
"We've embraced XML within PeopleSoft, within our application messaging facilities for PeopleSoft-to-PeopleSoft, and PeopleSoft-to-third-party publish-and-subscribe messaging. Now that the OAG has adopted XML as an underlying format, that helps."
Until now, the expected adoption of OAG standards was met with scepticism because of the difficulty of getting competing vendors to agree on both technology and business process definitions. SAP, which is migrating toward XML in R/3, is still offering its Business APIs (BAPIs) as the main means for third-party integration.
According to Guenther Tolkmit, senior vice president for marketing at SAP, users can either use the OAG's BOD standard or SAP's BAPI interfaces with XML as the underlying communications protocol.
XML not only lets you package and ship content, but it also describes information, Tolkmit said. For instance, when "1995" appears, XML characterises whether it is a date, a price, an order number, or a supplier code.
"This is why [OAG's use of XML] makes perfect sense," Tolkmit said.
The OAG is in the process of generating XML Document Type Definition (DTD) files - the glossary and explanatory notes accompanying XML documents - corresponding to the 84 transactions of the OAGIS' specification and will post them later this year or early in 1999, according to Kurt.
Mapping the XML message format to each application's native APIs - work currently being done by third-party middleware vendors - and validating messages against the OAG DTDs should provide reliable integration, Kurt said.
"It's another step toward getting away from stovepipe applications," said John Wick, a technology scientist at Science Applications, a systems integrator in the US. "If you're having the meta data floating along - if it's internally consistent - that's a step forward."