At its Impact conference in the US Monday, IBM announced an event-driven extension to its WebSphere platform for managing services in an SOA environment. Most SOA platforms have focused on centrally orchestrating services triggered by a process need, such as handling a customer lookup when a salesperson processes an order. But most SOA platforms have not been engineered to handle complex events, in which a pattern of activities -- both random and scheduled -- should trigger a set of services. These complex events are more common in high-transaction environments.

That event-blindness is now changing. IBM's WebSphere Business Events platform lets business users monitor and analyze events to see the connections among them that are not immediately obvious, then take action. The platform itself can identify connections and trigger actions as needed. For example, an unusual set of ATM transactions could indicate fraudulent activity taking place; WebSphere Business Events could detect the connection among those seemingly independent transactions and then initiate a security alert, or even shut down the ATMs in question.

As another example, based on the types of independent service calls received, the platform could identify a product defect by detecting the underlying pattern of the separate complaints, then triggering an alert to engineering or production of the possible defect.

There's nothing intrinsic about SOA that prevents an event-driven approach, but many SOA platforms didn't account for event-driven services in their designs, said Hub Vandervoot, CTO of Progress Software. (Its DataDirect Technologies unit announced the addition of event-driven capabilities for mainframe integration in SOA environments on April 4.)

The typical SOA platform orchestrates services centrally, assuming that what should be triggered is defined in a business process, Vandervoot noted, but that approach doesn't account for events that occur across or outside of specific business processes. Thus, the need for SOA platforms to extend to cover the event-driven model as well. "These are distinct engineering styles, and the choices as to which you use when are essential to the outcome," he added.

Among barriers to bringing an event-driven model to today's SOA platforms is a lack of standards, Vandervoot said, for publish-and-subscribe protocols a la RSS and Atom; instead, SOA platforms typically use a procedure-call style that pushes out the message to the ESB (enterprise service bus) or other orchestrator.

Similarly, the soon-to-be Oracle subsidiary BEA Systems has advocated the integration of event-driven architecture into SOA. Oracle itself has pushed the concept for several years under the "SOA 2.0" label.