SOA: Top Down, Bottom Up or Hybrid?
Conventional wisdom suggests that to achieve strategic approach to SOA, it is ideal that business centric nature of the Services be the guide to designing SOA.
But the dichotomy of SOA realization is that services are realized from existing systems, hence it necessarily mandates a role for bottom up approach to leverage legacy and EIS systems.
So it is top-down or bottom-up for SOA?
Meeting the best of both worlds from both top-down and bottom-up approaches are ideal to achieve the right balance, and right level of prescription for SOA deployment in enterprises.
One approach we suggest is Meet-in-the middle. Let business services be designed top-down.
Let realization of fine grained services be done bottom up from existing systems or new development.
Let there be a MEET-In-The-Middle approach via service impedence rationalization between the top-down and bottom-up approaches as the ideal panacea. A detailed analysis can be found at the paper titled :An Architectural Framework for Service Definition and Realization, presented at SCC 2006 . details at http://doi.ieeecomputersociety.org/10.1109/SCC.2006.97
Comments
Like any other technology adoption, there is rarely a purist approach. An organization needs to have focus on where it needs to reach in terms of SOA maturity and what capabilites it needs to adopt. To formalize the focus there is a bit of work which needs to go in at an Enterprise level which we can call it as 'Top-Down'. However considering the need for quick wins and leveraging the exisitng assets baby steps need to be taken from a bottom up point of view.
Posted by: Shreyas Kamat | January 4, 2007 06:46 PM