Services Layer

In my previous posts I showed layers and components, and layers and tiers. In this post, I'll show the services layer in a layered architecture.

Services Layer
Here's a visual example of a services layer, where the application is exposing services:

Note that services don't need to be "web" services.

Key Services Layer Components
Here's the key components of a services layer:

Service Interfaces. The service interface acts as a facade that exposes the business logic to potential consumers. The definition of the set of messages that must be exchanged with a service in order for the service to perform a specific business task is the contract.
Message Types. Message Types are “message contracts” for communication between service consumers and providers. They wrap business entity components into specific messages for the calling service.

Additional Resources

My Related Posts

patterns & practices App Arch Guide 2.0 Project

Comments

Anonymous
September 07, 2008
As part of our patterns & practices App Arch Guide 2.0 Project , I'm scanning Microsoft for helpful
Anonymous
September 10, 2008
So my question, in this diagram are you trying to show that layering is done in a strict way with no communication with the business layer other than through the service layer and then application facade?
Anonymous
September 11, 2008
One of my colleagues on the patterns & practices team, David Hill , collected and distilled feedback
Anonymous
September 17, 2008
As part of our patterns & practices App Arch Guide 2.0 project , we've created a set of application
Anonymous
September 24, 2008
As part of our patterns & practices App Arch Guide 2.0 project , we've put together an arch frame. 
Anonymous
November 11, 2008
Application Architecture Guidance Communiqué: Issue 1 About the Application Architecture Guidance 2.0
Anonymous
November 20, 2008
The comment has been removed