There has been plenty of talk about today's dynamic business environ¬ment and much has been written about it. Organizations face various challenges that force them to undergo dramatic changes to grow and be more profitable. These challenges include fierce competition from rivals, ever-changing re¬quirements for regulatory compliance, pressure to create new business areas and increase customer base, to innovate and generate new sources of revenue.

To overcome these challenges, organizations must change and adapt quickly to new trends without adversely affecting their core business functionalities. For this to happen they have to move out of the shackles of having siloed applications for different business processes towards a more flexible and seamless business envi¬ronment, where business processes are more integrated as well as flexible to changing requirements. SOA has emerged as a dominant technology for supporting such business transformations.

WhySOA?
Software engineers know from the begin¬ning of their software development cycle that software which changes frequently should be decoupled from software that changes infrequently. This principle, when applied to the information manage¬ment of an organization, becomes SOA. However, it is the practice of isolating core business functionalities into independent services that doesn't change frequently. These services are functions that are called by one or more presentation pro¬grams, and are nothing but interfaces that present data to and also accept data from users. To make things more clear about services, let's take an example of an online store. Visitors who browse the website of such a store are presented with content on their browsers through presentation soft¬ware.

This software interprets visitors I customers gestures and correspondingly invokes services that retrieve data of the product catalog that a customer is view¬ing or for registering a customer's order basket. The services that are called do not know that they are talking to a website; they could easily be talking to a thick client or even some other application such as an ERP solution. These services simply accept and return data in a standard for¬mat.

Now since change is part of life, the website too may undergo change with time. The presentation interface may be changed for different layouts or to incorporate new technologies such as Ajax. But none of this has to do anything with the core business functionalities that are en¬capsulated by these independent services that we talked about earlier. Similarly, if there is a change to the business logic, then these services have to be worked upon without changing the presentation software.

Service-Oriented Architecture (SOA) is a framework that sup¬ports transformation of an organization's business into a set of linked services, reusable and repeatable business tasks, which can be accessed over a network, be it a local intranet or the Internet. These services coalesce to achieve a specific business task of the organization.

Implementation scenarios
Two key benefits from an SOA implementation are: alignment of IT with business processes: and the ability to maximize the reuse of IT assets. So, the question arises: How should an organization tap into SOA? Let's take an example of a manufacturing company. Manufacturers have to respond to customer demands in time and also, to improve profitability, they must reduce complexities in busi¬ness and manufacturing processes. To manage different business processes, they adopt various applications, such as SCM for produc¬tion management, CRM for vendor and customer related informa¬tion management, etc. But each of these applications is restricted to their own domain, thus forming an obstacle for seamless information 110w.

Moreover, a manufacturer would like to integrate his supply chain with trading partners for better delivery of products, so that inventory shortfall or an urgent business contract demand could be met in time. With the implemen¬tation of SOA. the manufacturing company shall be able to integrate their various legacy systems by adopting a presentation framework that would enable data flow across these disparate systems, through a standard format, such as XML. And through the use of Web Services, they can collaborate or exchange information with their trading partners for business processes related to inventory manage¬ment over the Internet. Thus, by imple¬menting SOA, a manufacturing organization can achieve end-to-end manufacturing process integration, and have just one overall interface for the organization's business intelligence, coming from various information stores of disparate applications such as SCM and CRM. This inre¬turn streamlines their business process right from material procurement to production and finally the delivery of the product to customer.

SOA implementation can be done at various stages by an organization. IBM has defined five entry-points. These points are driven by both business and IT needs for an organization. The entry points relating to business needs of an organization are:

•People: Focus on user experience. to enhance collaboration and to improve business productivity.

•Process: Focus on the present busi¬ness model to transform business processes into reusable services and to optimize business processes.

•Information: Leverage the business information to all functional areas of the business.
The entry points pertaining to IT needs of an organization include:

•Connectivity: Effectively connect the infrastructure: integrating peo¬ple, processes and information in the organization and also to connect to communicate with external trading partners beyond an organization's firewall.

•Reuse: Focus on reusing existing serv¬ices and cutting down on duplication that results in reduced development time and ensure consistency across all business processes in the organization. Such entry points help an organization
to think and strategize their business needs and objectives to be fulfilled by means of SOA implementation.

For any organization, that is planning to move ahead with SOA, understanding this baseline perspective becomes really important: to decide what business processes should be configured to incorporate SOA. A proper SOA implementation for an organization or business would result in seamless information flow across heterogeneous applications, platforms and transmission protocols.