When Defense Department officials envisioned a sleeker, more efficient information technology infrastructure to support warfighting efforts, they committed to a hot but still unproven strategy known as a service-oriented architecture. SOA promises an orderly world of flexible and interoperable software components that perform specific data-handling functions. Developers can also dynamically mix and match SOA-managed services to create new applications and processes. SOA is gaining support at a growing number of agencies, but it resonated early with DOD.

"We had a notion of transformation of our IT infrastructure for warfare," said Rob Vietmeyer, chief engineer for the Defense Information Systems Agency's Net-Centric Enterprise Services program. "We wanted to increase our agility and provide for data access and function sharing at a scale larger than ever. We wanted to view this from the full enterprise perspective."

Two years into its SOA efforts, DISA is now creating a digital directory so developers across DOD can locate Web services waiting to be plugged into new SOA applications. Although the SOA project is still in development and only some small pilot tests are being conducted so far, Vietmeyer said the early results are encouraging.

To achieve SOA success, agencies have a growing list of building-block technologies that can bring SOA to life. The list of SOA must-haves, according to

Anne Thomas Manes, vice president and research director for Burton Group, includes the following:

• A development platform: For creating the actual Web services software code, development and application run-time tools include IBM WebSphere; Sun Microsystems’ Java 2, Enterprise Edition and JAX-RPC; Microsoft .NET; and an open-source option, Apache Axis.
• Registry: A virtual directory software program where “provider” Web services advertise to “consumer services” looking for a specific capability. Registries often use an evolving standard known as Universal Description, Discovery and Integration.
• Web services management: An Extensible Markup Language gateway that may either be a hardware or software component. These products monitor Web services traffic and alert systems administrators when problems arise. Management tools can also record business activity to create traffic pattern analyses to help administrators balance workload and optimize system performance. Vendors include Actional, AmberPoint, Layer 7 Technologies and SOA Software.
• Enterprise service bus (ESB): A main element for integrating Web services for legacy applications, ESBs monitor events and dispatch requests to launch necessary processes. For example, if a Web service requests replenishment of an inventory item, the ESB would start the series of events leading to restocking. Vendors include IBM, Fiorano, Sonic Software, Tibco and webMethods.
• Development governance tool: A testing tool, such as WebLayers Center, to verify that new services are built according to the organization’s compliance rules. The tool may issue a pop-up warning that a new service supports a necessary Web services standard.