Are realized by shared Services which are not owned by any single application, consist of their own lifecycle, and are managed independently.

May be implemented by existing applications, applications that are being developed, or proposed applications that have not yet been delivered.

Once handed to a project by the business, can be purely managed by that project.

Are focused on defining the integration points between applications,

Should only be managed by a SOA centre of excellence.

Point-to-point integrations should be avoided.

Integrations should be point-to-point using Web Services.

Message and data formats should be based on the native application data structures.

Extensive, intrusive modifications to existing applications should be avoided.

Service consumers should be able to migrate to a newer version of a SOA Service gracefully.

There should not be more than one version of a SOA Service in production concurrently.