Major players post web services spec

Microsoft, IBM and BEA have jointly announced the first draft of web services specifications for how to define, create and connect multiple business processes.

The specification could be the first step in unifying the approaches of the major vendors towards web services standards.

The business process execution language for web services (Bpel4WS) describes the flow of tasks in a long-running transaction. It supersedes a number of other draft specifications previously backed by BEA and others.

Bpel4WS - already being abbreviated to Bpel - is an XML-based flow language defining how the business processes will interact. It makes no assumption about the protocol and does not bind a web service to a specific operating environment.

Bpel uses WS-Coordination and WS-Transaction to describe multiple web services interactions that together make up a complete transaction.

WS-Coordination gives developers a structure under which the co-ordination of functions can take place. WS-Transaction lets businesses monitor the success or failure of each specific activity within the overall business process, handling faults detected during execution.

The problem all the previous specifications tried to address is automating business processes across companies in a standard way, something fundamental to the future of web services.

For example, a travel agent might offer hotel, flight and car rental reservations as a web service for customers. A complete transaction sequence with a customer could involve booking all of these in turn from third parties then giving the customer final confirmation.

"This is a real game-changer for the state of web services: a collective set of viable architectural specifications that provide a base for building heterogeneous web services across distributed platforms," said IBM fellow Tony Storey.

Neil Ward-Dutton, research director at analyst Ovum, added: "Potentially really good things will come of this. It's a really horrid state at present.

"The different standards all overlap and have different scopes. But this is only the first step in unifying the approaches of the major protagonists."

Ward-Dutton said he suspected that BEA, which had not contributed to the specifications, was hedging its bets because this had a good chance of succeeding.

"It's basically a race. The [company] that gets there first has a strong degree of control," he said.