(adapted from Naval Post Graduate School, Monterey, CA, Masters Thesis—SOA for Coast Guard Command and Control by Dash and Creigh, March 2007 — approved for public release):
- Know when to use services – Explicitly define the extent to which we will and will not use services; services are selected with intent and do not randomly spring up.
- Think big, start small – This allows us to validate the architecture, while giving the organization value, realized as usable services.
- Build on what you have – Reuse legacy application functionality and data wherever possible.
- Use SOA to streamline business processes – SOA is an inherently flexible and interoperable model for hosting application functionality; this provides an opportunity to rethink and improve business processes.
- Incorporate standards – Use industry web service standards for navigation, application logic, integration, data stores, and enterprise infrastructure.
- Build around a security model – Functional design needs to be built around security, and not vice versa (security cannot be added as an afterthought).
- Design with quality in mind – Quality must be designed into the product, and not inspected into it.
- Organize development resources – Group development team around logical business tasks, and not around technologies.
- Train developers – Ensure designers and developers have the skills to implement SOA properly.
SOA is a software design methodology that uses loosely coupled services to perform business functions and processes.
A service is an implementation of a well-defined piece of business functionality, with a published interface that is discoverable and can be used by service consumers when building different applications and business processes.
In general, I think SOA is a great fit with User-centric EA, because the focus is on providing functional business services to the end-user, as opposed to developing monolithic, stove-piped, and redundant applications. The end-user should not have to use countless non-integrated applications systems (or even computers) to get their information, but rather the information should be technically transparent and readily accessible based on their business requirements.