Services:


  • A “Service” is a self-contained, stateless business function that accepts one or more requests and returns one or more responses through a well-defined, standard interface.

  • Services can also perform discrete units of work such as editing and processing a transaction.

  • Services should not depend on the state of other functions or processes.

  • The primary goal of a service is to represent a “natural” step of business functionality.

Interoperability:


  • With heterogeneous systems, the first goal is to be able to connect those systems easily. This is usually called “high interoperability.

  • For SOA, high interoperability is the beginning. It is the base from which we start to implement business functionality (services) that is spread over multiple distributed systems.

  • Services can be called from any other systems, they are inherently interoperable

  • So basically the service (business functionality) is a reusable component.


Loose coupling:


  • Loose coupling is the concept of reducing system dependencies.

  • Business processes are distributed over multiple back-end, it is important to minimize the effects of modifications and failures.

  • Loose coupling offers:
         –Flexibility
         –Scalability
         –Fault tolerance