Many organizations will look for temporary solutions—say middleware—to overcome a lack of mature standards. “From the CIO’s perspective there’s a lot of pressure to adopt a middleware platform to fill in where standards are not there, but in a way that doesn’t lock them into it,” says Jim Stogdill, CTO at Gestalt LLC, a defense and energy consulting firm that helps clients launch SOA projects.

But it’s important not to commit too much to one middleware vendor, “because it will be much more disruptive later to swap out,” he says.

Stogdill advises organizations to stick with fairly common standards such as SOAP and WSDL, “and also look to where your line of business application vendors are providing services: Then integrate line of business applications via those service interfaces using unintrusive middleware.

GM’s Selective Strategy
For its part, General Motors learned in its early SOA efforts to identify which standards were most important to what the company was trying to achieve. GM launched its first SOA project in 2000, an architecture called Northstar, for its global online vehicle showroom services (GM Global BuyPower). Northstar’s goal: to establish a global common SOA plan flexible enough to support the dynamics of GM’s business, Zhang says. To achieve this, GM designed the architecture to separate business functions from business process flow (the sequence of the business functions to be performed). The company also separated the physical locations of business data from those of the business functions using the data, and user interfaces from the business process flow, business functions, and business data, Zhang says.

GM successfully deployed the Northstar architecture in more than 40 countries in 2001. The architecture helped GM fulfill various business needs quickly, such as meeting data location regulations, making business process flow changes based on business engagement rules and varying the end user’s software experience based on culture differences in individual countries, Zhang says.

Since the company also uses SOA in other consumer-focused online services, including GM OnStar services, it plans to develop an enterprisewide strategy and governance program for broad deployment of SOA internally and with external partners, Zhang says. As part of the planning for GM’s next-generation SOA implementation, he’s evaluating the latest enabling standards and technologies.

For GM today, the most important specs are those that help standardize the interfaces among services across the well-defined service layers (presentation, business process and so on) The next most important are those that help standardize the implementation of the services within each of the service layers.