Tuesday, February 24, 2009

SOA: Under Construction

CIO - SOA: Under Construction
The ultimate objective of SOA is a supremely agile infrastructure, where IT develops composite applications atop of a layer of abstraction that spans multiple platforms and domains across the enterprise. But nobody can "boil the ocean" and achieve that goal all at once. Practical SOA initiatives begin with a related set of business processes that would clearly benefit from greater flexibility -- where market conditions are in constant flux, for example, or new services must be deployed on the fly for competitive reasons. At some point that top-down approach meets the bottom-up reality of existing software assets and infrastructure.

The link at the beginning is an article from December 2006. An informative read for those thinking of utilising SOA as part of their IT strategy. It talks about tactical issues such as,
  • Building, exposing, and monitoring services
  • Whether to go for an ESB or not and why?
  • Security and Governance
  • Testing and Debugging Services
Then the article explores the approach to be taken when selecting a SOA Platform with the following caveat.
"The choice of development platforms, registries/repositories, management schemes, messaging systems, security technology, and testing tools is dizzying. It's easy to get caught up in tactical decisions, such as whether to buy an ESB and from whom. But the approach you pick should come after you have defined your business processes, core services, and overall architecture."
It concludes by highlighting the value of high level architecture compared to certain tactical decisions. Pioneers such as BT (British Telecom) are quoted throughout the article with examples where applicable.
Britain's telecom giant BT has developed 14 service platforms. "Each platform has a set of services that have operations associated with them -- like a method in object-oriented programming. A service resides in one and only one platform," BT's Glass says. And each platform has an architect assigned to it, who ensures that all services -- whether developed in-house, provided by a partner, or bought from a vendor --
adhere to the architecture. To enforce that compliance, if a BT project doesn't meet the architecture, the development team loses a quarter of its annual bonus.