IBM, Microsoft and BEA Systems on Monday will release a trio of proposed Web services specifications designed to answer nagging questions around reliability, integrity and business process workflow that are swirling around the emerging technology.
The highlight is a specification called the Business Process Execution Language for Web Services (BPEL4Ws), a workflow language that describes the number of Web services that need to be executed, the order in which they are executed and the type of data they share.
The specification is a combination of IBM's Web Services Flow Language (WSFL) and Microsoft's Xlang, two formerly competing efforts to create a workflow standard for Web services.
The trio of vendors also is introducing WS-Coordination, which offers the reliability that all the actions of a distributed application have executed as planned, and WS-Transaction, which rides on top of the WS-Coordination and ensures that a transaction is completed fully or that it is rolled back if all the actions are not executed.
The three specifications will work in harmony to solve the workflow issues involved in connecting and executing a number of Web services that may be running on disparate platforms internally or across multiple enterprises especially in an electronic commerce scenario.
Web services technology is sorely lacking a set of standards that would allow enterprises to go beyond the simple integration of two systems. What is needed is a sophisticated merging of a number of Web services to support a business transaction such as coordinating the booking of an airline flight, a hotel and a car rental into a single itinerary.
"We think these specifications will significantly increase the number of business problems that enterprises can solve with Web services," says Karla Norsworthy, director of dynamic e-business technologies for IBM. "You can model business processes that include a number of Web services and then you can bring in a level of reliability and dependability with WS-Coordination and WS-Transaction. People need to know that a whole business process executed. "
Norsworthy says a key to BPEL4WS is that it is an executable language, which means it can be used to not only write business processes but also to execute them. It also will allow developers to publish their business processes so other applications can call and execute those processes as part of their own workflow.
In terms of execution, BPEL4WS would allow a business process to interpret the data returned by any of the Web services in the workflow and act on that data. For example, if a business process was used to book an airline flight for someone arriving on a Tuesday morning and leaving on a Tuesday night, that workflow could look at that data and know not to execute the Web service that books a hotel for that traveler.
This is the second set of significant specifications IBM and Microsoft has teamed up to create. In April, the pair along with VeriSign developed WS-Security, a specification for securely exchanging Web services messages. The specification was recently accepted by the Organization for the Advancement of Structured Information Standards (OASIS) as a proposed standard.
The latest standards effort on business process workflow will intersect with that work. "People writing business process workflow using these new standards may want to incorporate WS-Security," says Steven VanRoekel, director of Web services marketing for Microsoft. "It will all be designed to work together in the same architecture. It's all joining together to solve the plumbing problems that exist in Web services."
The business process workflow effort of IBM, Microsoft and BEA, however, is not the only work being done in this area.
Sun recently introduced its Web Services Choreography Interface (WSCI), which it co-developed with BEA. WSCI on Thursday was recognized by the World Wide Web Consortium (W3C) as an official submission that it will publish, but WSCI has not been placed on a standards track.
Also, the ebXML specification, a set of XML-based definitions for electronic transactions that is being developed by OASIS, has its own protocols for business process workflow.
"We see a need for convergence of work within standards bodies to reduce the complexity of Web services," says Ed Julson, group-marketing manager for XML and Web services at Sun. "The fact that IBM and Microsoft have combined their work [around workflow] is a good step."
Julson says if the duo's most recent work on business process is presented to a standards body and is unencumbered by royalty fees then Sun would consider supporting it just like it did with WS-Security.
"The work that was done on WS-Security was a good example for the industry, and if this most recent effort happens that way there is a good chance that Sun would support it," says Julson. He added that the decision obviously would hinge on the specifics of the specification, which Sun has yet to see.
IBM, Microsoft and BEA said they intend to eventually submit their work to a standards body, although they did not say which one.
The specifications will be published on the vendors' Web sites on Monday.