This page shows a Data Integration Architecture,
and we have listed some vendors.
We have designed a Service Oriented Architecture, (SOA),
along with a Generalised Customer Data Model
which is oriented to a local or national,(eg State or Federal),
Government providing Services to its Citizens.
Underpinning this work is a Data Repository or Information Catalog holding details of Source Applications,
Tables, Columns and Mappings of all Sources to the Target Generalised Model.
If you are interested in the more general context of Enterprise Architectures,
then check out John John Zachman's Framework which
is most commonly regarded as the point of reference in this area.
Also, check out this
Architecture and Governance magazine, which has interesting and relevant articles.
Finally, here's an overview diagram that reflects a project I worked on a few years ago.