Step by Step, Into a Service-Oriented World

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August 02, 2007

Step by Step, Into a Service-Oriented World

"The key to successfully doing something is in successfully understanding what you're doing."

With these words of wisdom, Thomas Erl, noted author and analyst on all things SOA, kicks off his latest book, SOA: Principles of Service Design, which covers many of the fundamentals of SOA. Erl's goal in publishing the work is to help developers, architects, and IT managers evolve into "true" SOA professionals that can deliver service-orientation to the enterprise.

The book is packed with information and insights, and here are just a few observations Thomas makes about moving to service orientation:

There's nothing "new" about SOA: Interestingly, Thomas points out that "service orientation has deep roots in several past computing platforms and design approaches, and is therefore not considered a revolutionary design paradigm."

SOA benefits are many: Thomas points out that the "key benefits of service-oriented computing are associated with the standardization, consistency, reliability, and scalability established within services." He adds that SOA "provides the potential to elevate the responsiveness and cost-effectiveness of IT."

Reuse is important, but not the whole story: While reuse of services is seen as the best route to economies of scale, Thomas points out fast and efficient integration is a benefit that can stand on its own. In fact, in many surveys I have seen and conducted in recent years, integration continues to be the main driving factor to SOA. Thomas affirms that "if reusability were to be omitted as a design characteristic, significant interoperability-related benefit would still be attainable."

SOA is ultimately about the enterprise: Thomas points out that as SOA gains more traction within an organization, the reach of IT architecture begins to expand beyond traditional boundaries as well. "The enterprise perspective becomes increasingly prominent," he points out.

SOA is mainly about Web services: While many observers argue that SOA is about all types of services, Thomas argues that Web services is clearly the driver of SOA, and vice-versa. Web services is "primarily responsible for the popularity of SOA," he says. "Conversely, the rise of service-oriented computing has repositioned and formalized the Web services technology set from its original incarnation." Thomas also states that "Web services currently provide the foremost means of implementing services."

Silos weren't all that bad, but SOA is better: The traditional silo-based approach to building applications, Thomas observes, "has been successful at providing tangible benefits and measurable returns on investment." However, he adds, silo-based computing increased complexity and administrative burdens on IT." SOA eventually reduces this complexity and burden, he adds.

SOA may be more expensive and complex -- at first. While SOA can reap significant long-term benefits, Thomas also cautions that it's not easy getting it all started. SOA introduces "design complexity and the need for a consistent level of standardization," noting that the "construction of services can be expensive and time-consuming, introducing a more burdensome project delivery lifecycle, further compounded by some of the common top-down analysis requirements that need to be in place." SOA also has the effect of shaking up the IT organization, he adds.

Posted by joemckendrick in SOA | Digg This | Add to del.icio.us