Page 490 - Handbook of Modern Telecommunications

Network Organization and Governance 4-21

4.2.5.1 Service-Oriented Architecture (SOA)
Service-oriented architecture (SOA) is a client/server software design approach in which an application
consists of software services and software service consumers (also known as clients or service request-
ers). SOA differs from the more general client/server model in its definitive emphasis on loose coupling
between software components, and in its use of separately standing interfaces. SOA principles are ren-
dered during application design, development, and deployment. These renditions share the essential
principles of encapsulation and flexible coupling, but they differ in detail. The fundamental intent of SOA
is the nonintrusive reuse of software components (services) in new runtime contexts. The design and
development of SOA is performed for the purpose of achieving such an agile runtime environment.
SOA provides a framework for software on one system to securely and reliably request and receive
computational resources on other systems. SOA is the latest answer to the perennial problem of reduc-
ing the complexity and interdependencies of componentized software systems. SOAs today are built
on Web services, delivered primarily as Simple Object Access Protocol/XML interfaces, Web Services
Description Language definitions, and on Universal Description, Discovery, and Integration Protocol.
Services are building blocks that can be used to construct complex systems across a distributed network.
SOA represents a fundamental break with client/server. Instead of a master–slave relationship between
servers and clients, systems now can communicate in a distributed peer-to-peer relationship similar to
routers in IP networks.
The Service-Oriented Business Application (SOBA) perspective is that applications are delivered as a
set of packaged software services, as opposed to monolithic application modules. These applications will
have process orientation and flexibility that goes beyond the traditional monolithic application suites.
The platform for such applications combines the infrastructure of application server and integration
broker with portal, analytics, content management, and collaboration support technology. SOA and
integration with established application systems are prerequisites for these products.
The Service-Oriented Development Application (SODA) is the development paradigm for building
applications on an SOA. Using services as the primary unit of modularity requires a new approach
that involves composing applications from sets of loosely integrated processes. This is the assembly list
approach, rather than a code first approach used in traditional development. Code is necessary in a
SODA world, but it is hidden behind the service interfaces. This means that consumers do not need to be
concerned with the structure or technology of the underlying program logic and platform.

4.2.5.2 Business Service Management
End-to-end IT service management embodies the people, processes, and technologies that an IT service
provider must employ to develop, deliver, and support appropriate and competitive IT services at the levels
necessary to support business goals. IT operations departments are moving from a component orientation
(such as networks, servers, storage, database, and applications) to managing business-oriented, end-to-
end IT services. Business units that lack interest in individual IT components are driving this evolution.
They want the end-to-end IT services that support their business processes to be available and perform to
meet their needs. Yet because IT operations departments have been so segregated in component-oriented
organizational structure and metrics, this transition is challenging for most of them.
By taking an end-to-end IT service management approach, IT organizations can achieve many bene-
fits. Aligning IT infrastructure components with business-oriented IT services helps IT operations staff
understand the business impact of IT problems. This results in improved availability, reduced downtime,
and shorter problem resolution time because IT support focuses on solving the correct, high-priority,
business-relevant issues. Because there is less “firefighting” and more repeatable processes, labor costs
are reduced. In addition, taking an IT service management approach enables more productive com-
munication between the IT organization that delivers the services and the business users who consume
them. This raises the IT organization’s credibility with the business by demonstrating its understanding
of how IT services support business processes.