Basic Principles for Building SOA

There are some basic principles for building a service oriented architecture, which I have gone through while reading a book - 

" Service-Oriented Architecture: Concepts, Technology, and Design By Thomas Erl"

Below are some of the key points: -

1. Loose coupling Services maintain a relationship that minimizes dependencies and only requires that they retain an awareness of each other.
2. Service contract Services adhere to a communications agreement, as defined collectively by one or more service descriptions and related documents.
3. Autonomy Services have control over the logic they encapsulate.
4. Abstraction Beyond what is described in the service contract, services hide logic from the outside world.
5. Reusability Logic is divided into services with the intention of promoting reuse.
6. Composability Collections of services can be coordinated and assembled to form composite services.
7. Statelessness Services minimize retaining information specific to an activity.
8. Discoverability Services are designed to be outwardly descriptive so that they can be found and assessed via available discovery mechanisms.