Enterprise SOA

Chapter FOUR. ESA Fundamentals: Learning to Think ESA

The preceding chapters provided an overview of ESA, along with a survey of ESA's business value and information on how a company can evolve toward ESA. While these chapters effectively set the context for a deeper discussion of ESA, more work remains. ESA is essentially a new way of thinking about how enterprise applications are constructed and how they are used to support a business. At almost every level, ESA reshapes traditional thinking, introduces new concepts, and sets forth a new paradigm for building IT to support the needs of modern businesses. This chapter will introduce and explain the ideas that are fundamental to the transformation of IT that ESA will achieve.

What is architecture and why is it important?

In essence, architecture is a contract that organizes the work of hundreds of thousands—or even millions—of people. It describes the structures used in the course of that work, which in the case of software refers to data and other abstract mechanisms that will have a certain responsibility and that will be connected in a standardized way.

Architecture makes these standard abstract mechanisms or components useful by clearly defining the relationships between them. Complex, unwieldy systems can be reduced to their essence—i.e., to these relationships—and it becomes possible to see which pieces of the system are the most important. It works both ways: if you are attempting to create a piece of software that fits into ...