B2B Integration : A Practical Guide to Collaborative E-commerce

326 B2B Integration — A Practical Guide to Collaborative E-commerce
11.1. Service Oriented Architecture (SOA)
We have discussed in the previous chapters that B2Bi involves dynamic
integration of heterogeneous applications and platforms across multiple
organizations. A minor alteration in just one of the applications, at one
of the firms, can break the whole integration.
For true dynamic integration, software resources such as applications,
objects and programs should be loosely coupled. These resources should
make their presence known to the world and provide public interfaces,
which describe their actions. The communication between these resources
and the applications using them should occur, based on open standards.
Using these resources, which can be personalized for each user, the
future applications would be built dynamically within seconds.
This is where SOA comes into the picture. It provides a framework
and architecture for interconnecting applications and software components
seamlessly. It provides the ability to invoke remote business services
and install them as local components in a different application, all without
writing a single line of low-level code.
11.1.1. Components and operations of SOA
There are three components of service oriented architecture (see
Figure 11.1). They are:
• Service Provider — This component is responsible for creating and
publishing the interfaces of services, providing the actual implementation
of these services and responding to any requests for the
use thereof. Any company or business can be a service provider.
• Service Broker — This component registers and categorizes public
services published by various service providers and offers services
like search, etc. Service brokers act like a repository or yellow pages
for Web services. Companies that want to use Web services can
search these yellow pages to find one matching their needs. Currently
several companies including Ariba, IBM and Microsoft are acting as
service brokers.
• Service Requester — This component is the actual user of Web
services. Service requesters discover Web services by searching the
repository maintained by the service brokers and then invoke these