Page 100 -

76 Chapter 3 • Enterprise Systems Architecture

reusability, and flexibility. SOA offers the following benefits over traditional approaches to
distributed computing:

•Business-level software services across heterogeneous platforms
•Complete location independence of business logic
•Services can exist anywhere (i.e., any system and any network)
•Loose coupling across application services
•Granular authentication and authorization support at service unit level
•Dynamic search and connectivity to other services

Short-term benefits of SOA:
•Enhances reliability of the architecture
•Reduces hardware acquisition costs
•Leverages existing development skills
•Accelerates movement to standards-based server and application consolidation
•Provides a data bridge between incompatible technologies
Long-term benefits of SOA:

•Provides the ability to build composite applications
•Creates a self-healing infrastructure that reduces management costs
•Provides truly real-time decision-making applications
•Enables the compilation of a unified taxonomy of information across an enterprise and its
customers and partners
Business value benefits of SOA:
•Increases the ability to meet customer demands more quickly
•Lower costs associated with the acquisition and maintenance of technology
•Empowers the management of business functionality closer to the business units
•Leverages existing investments in technology
•Reduces reliance on expensive custom development
SOA also has its drawbacks. It brings changes in architectural style, programming models, best
practices, patterns, testing, and management approaches, and the collective learning cycle will take
some time. SOA focus is on business process with an underlying assumption that not everything in
technology can be the same, so standard methods and processes must be defined to enable disparate
technologies to communicate, regardless of manufacturer or language. For example, SOA requires:

•System environment consisting of numerous complex structures for integration
•SOA implementations, which are costly and time consuming
•Maintenance environment to support rapid integration capability within these structures
•Organizational culture that embraces the rapid sharing of assets and information
•Management approaches to support rapid sharing and integration
•Complex security firewalls in place to support communication between services across
applications that traverse the organization’s networks
The key limitations of SOA, therefore, are as follows:
•Performance can be inconsistent
•Requires enterprise-level focus for implementation to be successful