What are the biggest advantages to moving from n-tier to SOA?

Question

At my company we are currently using the classic n-tier architecture using NHibernate as our persistence layer with fat objects. Seeing many issues with this pattern, such as full hydration of the object graph when entities are retrieved from the database we have been looking in to other alternatives.

In this process we have moved to a more scalable Command and Query architecture, and now we are looking into the viability of SOA.

In your experiences, what are the biggest advantages of SOA over n-tier. Have you encountered any major hurdles?

And advice and reading material would be helpful.

Answer 1

Besides scalability, SOA offers architectural flexibility. If you decide at some point to move your application from WebForms to Silverlight, both can take equal advantage of a well-designed SOA interface.

You can also decide at some point down the road to offer a new service that takes advantage of some of the features and/or data in your current offering. You just build a new application that is authorized to access your existing interface and away you go.