Appendix A: Patterns for E-Business

---

IBM Patterns for e-business is a set of proven architectures that have been compiled from more than 20,000 successful Internet-based engagements. This repository of assets can be used by companies to facilitate the development of Web-based applications. They help an organization understand and analyze complex business problems and break them down into smaller, more manageable functions that can then be implemented using low-level design patterns.

Introduction to Patterns for e-business

As companies compete in the e-business marketplace, they find that they must re-evaluate their business processes and applications so that their technology is not limited by time, space, organizational boundaries, or territorial borders. They must consider the time it takes to implement the solution, as well as the resources (people, money, and time) they have at their disposal to successfully execute the solution. These challenges, coupled with the integration issues of existing legacy systems and the pressure to deliver consistent high-quality service, present a significant undertaking when developing an e-business solution.

In an effort to alleviate the tasks involved in defining an e-business solution, IBM has built a repository of patterns to simplify the effort. In simple terms, a pattern can be defined as a model or plan used as a guide in making things. As such, patterns serve to facilitate the development and production of things. Patterns codify the repeatable experience and knowledge of people who have performed similar tasks before. Patterns not only document solutions to common problems, but also point out pitfalls that should be avoided. IBM Patterns for e-business consists of documented architectural best practices. They define a comprehensive framework of guidelines and techniques that were actually used in creating architectures for customer engagements. The Patterns for e-business bridge the business and IT gap by defining architectural patterns at various levels, from Business patterns to Application patterns to Runtime patterns, enabling easy navigation from one level to the next. Each of the patterns (Business, Integration, Application, and Runtime) help companies understand the true scope of their development project and provide the necessary tools to facilitate the application development process, thereby allowing companies to shorten time to market, reduce risk, and most important, realize a more significant return on investment.

The core types of Patterns for e-business are:

• Business Patterns

• Integration Patterns

• Composite Patterns

• Application Patterns

• Runtime Patterns and matching product mappings

When a company takes advantage of these documented assets, they are able to reduce the time and risk involved in completing a project.

For example, a line-of-business (LOB) executive who understands the business aspects and requirements of a solution can use Business patterns to develop a high-level structure for a solution. Business patterns represent common business problems. LOB executives can match their requirements (IT and business drivers) to Business patterns that have already been documented. The patterns provide tangible solutions to the most frequently encountered business challenges by identifying common interactions among users, business, and data.

Senior technical executives can use Application patterns to make critical decisions related to the structure and architecture of the proposed solution. Application patterns help refine Business patterns so that they can be implemented as computer-based solutions. Technical executives can use these patterns to identify and describe the high-level logical components that are needed to implement the key functions identified in a Business pattern. Each Application pattern would describe the structure (tiers of the application), placement of the data, and the integration (loosely or tightly coupled) of the systems involved.

Finally, solution architects and systems designers can develop a technical architecture by using Runtime patterns to realize the Application patterns. Runtime patterns describe the logical architecture that is required to implement an Application pattern. Solution architects can match Runtime patterns to existing environment and business needs. The Runtime pattern they implement establishes the components needed to support the chosen Application pattern. It defines the logical middleware nodes, their roles, and the interfaces among these nodes in order to meet business requirements. The Runtime pattern documents what must be in place to complete the application, but does not specify product brands. Determination of actual products is made in the product mapping phase of the patterns.

In summary, Patterns for e-business captures e-business approaches that have been tested and proven. By making these approaches available and classifying them into useful categories, LOB executives, planners, architects, and developers can further refine them into useful, tangible guidelines. The patterns and their associated guidelines enable the individual to start with a problem and a vision, find a conceptual pattern that fits this vision, define the necessary functional pieces that the application will need to succeed, and then actually build the application. Furthermore, the Patterns for e-business provides common terminology from a project's onset and ensures that the application supports business objectives, significantly reducing cost and risk.

---