Business Motivations for Web Services
The vision of global e-business largely remains unrealized. Executives dream about seamless interactions both with other companies as well as e-marketplaces, but the tech-nology lags behind the vision. Today’s information technology is still extraordinarily complex and expensive. Even with standards such as Electronic Data Interchange (EDI), Java 2 Enterprise Edition (J2EE), Common Object Request Broker Architecture (CORBA), and Windows Distributed interNet Application (Windows DNA), communi-cating between different corporate systems is still filled with hair-pulling detail work.
The business world needs more powerful techniques to scale business solutions without increasing complexity to unmanageable levels. In addition, there is a clear need for open, flexible, and dynamic solutions for enabling global e-business interactions among sys-tems. The Web Services model promises to deliver these solutions by addressing com-plexity and costs, providing a common language for B2B e-commerce, and enabling the vision of a global e-marketplace.
Managing Complexity and IT Costs
In the early days of business computing, mainframes were large, complex, and expen-sive, and so were the programs that ran on them. As these systems aged, it was often pro-hibitively expensive to replace them, so programmers added functionality by adding code, thus building layer upon layer of complexity.
Object-oriented programming arose in this environment as an answer to the problems resulting from the ever-increasing complexity of the legacy systems. Modularity and reusability were touted as the solutions to the problems of legacy programming. Unfortunately, the promised gains generally did not materialize because of the complexi-ties inherent in distributed systems.
Remote procedure call (RPC) architectures arose to address the problems that developed when components on different systems needed to communicate with each other. The two most successful RPC architectures, DCOM and CORBA, have gained widespread accep-tance, but they are still too complex to provide convenient interoperability among differ-ent systems.
The conventional view of complex systems is that complexity and power are directly cor-related: Powerful systems are necessarily complex, and simple systems are necessarily of limited use. However, current research on complex systems contradicts this conventional wisdom. It is possible to build powerful systems with simple components (such as Web Services) that are smart enough to organize themselves into large, powerful systems. Such systems would retain the simplicity of their components as well as reduce the costs inherent in large, complex systems. (A good place to learn about complex systems is at http://www.brint.com/Systems.htm.)
Lingua Franca of B2B E-Commerce
Business to Business (B2B) e-commerce has been around for more than a decade in the form of the Electronic Data Interchange (EDI). EDI is quite powerful and has gained widespread acceptance but is limited by its semantic ambiguity. For example, a “quan-tity” field in a given form may stand for number of boxes for one company but the num-ber of pallets for another. People have to resolve each ambiguity manually, making EDI useful primarily in a hub-and-spoke arrangement, where one large company can dictate the meaning of each field to its suppliers.
When the Internet opened up the prospect of many-to-many e-commerce, it soon became clear that there needed to be a way to agree upon a single business vocabulary for all par-ticipants in each trading group. XML provided the basis for building such vocabularies because of its inherent extensibility. However, XML’s greatest strength also proved to be a weakness, because its extensibility led to hundreds of different business vocabularies, often with overlapping applicability.
The Web Services model addresses this Tower of Babel problem by providing for dynamic service descriptions. Individual Web Services can describe their interfaces at runtime, allowing for dynamic interpretation of the semantics of the XML that underlies the messages Web Services send and receive.
Global E-Marketplace Vision
The overarching vision behind e-business is a world with global, seamless, automated e-commerce. Each company’s systems should be able to locate and transact with other companies’ systems automatically. Unfortunately, this vision is still far from becom-ing a reality.
Today, integrating commerce systems from two companies requires preexisting business and technical relationships between the companies. Only then can the technology teams of the two companies get together and decide how they will communicate and handle business transactions.
Business requires a way for companies to locate, identify, contact, and transact with other companies around the world on a “just in time” basis—that is, without having to establish a technical relationship beforehand.