Today's Internet-driven business environment is forcing companies to become more agile, enabling them to react quickly to changes in global markets and respond decisively to moves by competitors. At the same time, companies also need to use disparate internal and external systems as never before.

Web Services, which are increasingly manifest in the corporate world through Service Oriented Architecture (SOA) initiatives, address a number of the challenges and requirements facing the corporate world. These new paradigms are dramatically altering how applications are defined, developed, and used to support the needs of the enterprise.

In this article we examine the impact Web Services as a technology have had on enterprise IT. We'll specifically focus on the connectivity Web Services provide; the evolution of software development from silos of functionality to SOA; and some of the benefits reaped from adopting the Web Service paradigm.

Web Services Enable Connectivity
Much of the initial interest in Web Services originated with the promise of integration across disparate systems. Although integration is typically the term used to describe such efforts, what companies are really striving for is connectivity; that is, the ability to connect not just the hundreds or even thousands of internal legacy and homegrown solutions, but to connect with external systems beyond the firewall.

In fact, more than 60% of IT projects initiated today are focused on integration. These projects have traditionally fallen into two categories: enterprise application integration (EAI) projects, with a focus on using mainframe-based solutions in the enterprise; and business-to-business (B2B) integration, with the goal of connecting the enterprise with customers, partners, and suppliers.

Before the advent of Web Services, companies typically had to build or buy EAI and B2B solutions separately, because they were often based on proprietary technologies. This wasn't only costly; it also required extensive resources to implement and maintain these various systems. The need for such resources provided steady employment to legions of IT consultants.

Web Services changed the equation by defining a single set of standards for integration both inside and outside the enterprise. This means that Web Services can address the requirements of B2B and EAI in an almost uniform way, with the exception of policies and management aspects.

The result is that companies have been able to extend the lifespan of existing IT assets such as legacy systems and proprietary systems, as well as collaborate more tightly with external companies, all while leveraging the Web Services paradigm.

This is not to say that connectivity has been achieved painlessly; indeed, integration continues to present challenges. Despite the fact that Web Services have empowered companies to create new business opportunities out of existing IT assets and interoperate with external systems as never before, an inevitable cost - complexity - can be incurred when things go too far. In particular, creating too many interdependencies across different lines of business can hurt the goal of business agility.

Web Services Redefine How Enterprises Approach Application Development
The days of the monolithic application development project may very well be over, deferring to the lighter, more-agile Web Services paradigm. This represents a fundamental shift in the way enterprises plan, develop, and integrate new applications.

Companies have come to view the reuse of existing assets as central to their development process. Instead of building new applications, companies are now investing time and resources in expanding portfolios of Web Services, looking both internally and externally to discover services that can fulfill specific needs.

Indeed, companies are now realizing that it's often more practical to buy or borrow functionality than to build it. Rather than implementing and maintaining the vertical applications themselves, companies can now leverage existing functionality provided by the vendors of those products.

A classic example is Google's publicly available Web API services, which enable developers to enhance any application with the ability to search billions of Web pages. A new niche market of sites such as StrikeIron, which is a sort of an eBay for Web Services, is slowly evolving, enabling companies to discover and buy access to services to leverage in their own applications.

The business implications of providing access to vertical applications exposed as services are even more promising. Most vendors of enterprise-level software such as customer relationship management (CRM) and enterprise resource planning (ERP) systems already expose their offerings via Web Service interfaces.

Vendors such as Oracle are offering customers even more options by exposing entire packaged application suites that provide vertical business functionality as Web Services. With such suites, enterprise customers can build out mission-critical applications and processes that are actually composed of a number of best-of-breed solutions.

The availability of such third-party services has reduced the overall effort required to bring a new solution online, not least because it reduces the demands on those involved. A company analyst tasked with specifying an order management system no longer needs to figure out how to integrate the new application with a commercial ERP product; he can simply search the enterprise portfolio for the ERP service that meets his needs. And the developer who implements the solution can simply integrate the appropriate service into the project without regard to how the back-end application is implemented.

Web Services have also helped reduce the gap that has traditionally existed between the IT and business sides of the enterprise. Traditionally, the business side provides IT with a set of requirements that IT then attempts to interpret. But because each side approaches the issue with a different perspective, problems simply understanding the issues, let alone addressing them, are inevitable.

With Web Services, both sides are now speaking the same language - the language of business - with more productivity and fewer cycles as the result. The human-friendliness of Web Services is key to its success; non-technical business stakeholders are more likely to be able to make sense of service interfaces. Instead of getting bogged down in details, IT can now take basic requirements and represent them as interfaces that senior management and business analysts can understand.

Of course, lack of communication was only part of the problem in traditional development practices. Once requirements were more or less communicated, the complexity involved in implementing them posed yet another challenge. For example, a typical request for minor functionality from the sales organization entailed having to map each requirement to numerous remote procedure calls. Web Services allow requirements to be abstracted as services, enabling far fewer mappings and reduced complexity on the business-facing front-end.

That is not to say that the challenge for IT has completely disappeared; the back-end business components can be just as complex as ever. However, the interface into the business logic implementation is far easier to understand, resulting in fewer misinterpreted requirements. And unlike the past, the enterprise can now look to external solutions that map to its requirements, rather than focusing exclusively on in-house development.

Therefore, it's clear that Web Services have made the concept of the adaptive agile enterprise a reality. Because services are granular to a specific part of the system, systems can evolve with the business.