Saas - Guiding Principles of SOA

Standardized service contract
- Services adhere to a communications agreement, as defined collectively by one or more servicedescription documents
Service abstraction
- Beyond descriptions in the service contract, services hide logic from the outside world.
Service loose coupling
- Services maintain a relationship that minimizes dependencies and only requires that they maintain an awareness of each other.
Service autonomy
- Services have control over the logic they encapsulate.
Service reusability
- Logic is divided into services with the intention of promoting reuse.
Service granularity
- A design consideration to provide optimal scope and right granular level of the business functionality in a service operation.
Service statelessness
- Services minimize resource consumption by deferring the management of state information when necessary
Service composability
- Services are effective composition participants, regardless of the size and complexity of the composition.