The tasks required to create an application that access the AppFabric Service Bus are as follows:

1. Create a service namespace. This service namespace contains the resources used by the AppFabric Service Bus to support the application.
2. Define the AppFabric Service Bus contract. A contract specifies the signature of the service, the data it exchanges, and other required inputs, behavior specifications, and object invariants.
3. Implement the contract. To implement a service contract, create a class that implements the interface and specify custom runtime behaviors.
4. Configure the service by specifying endpoint and other behavior information.
5. Build and run the service.
6. Build and run the client application.

As with any iterative, service-oriented software development, it may not always be appropriate to follow the preceding steps sequentially, or even start from step 1. For example, if you want to build a client for a pre-existing service, you start at step 5. Or, if you are building a host service that others will use, you can skip step 6.

Source: http://msdn.microsoft.com/en-us/library/ee173580.aspx

Sarang, K