In several chapters, but especially in Chapter 4, we stressed that any company transitioning to e-business development must first develop a comprehensive software architecture that will support all its subsequent application development efforts. In Chapter 5 we stressed that an enterprise e-business architecture was necessarily a distributed, component-based architecture. In this chapter we want to define such an architecture in more detail.

What Is an Architecture?

The term "architecture" is currently used in computing circles in so many different ways that it is meaningless without a specific definition. Broadly, most organizations have corporate hardware and software architectures. In general, these architectures are statements of the various types of hardware or software the corporation has decided to employ. The goal of architectures at this high level is simply to minimize the number of hardware platforms or software techniques used in the hope that standardization will make integration easier and reduce staff training and maintenance and support requirements.

Throughout this book, we ignore hardware architectures and focus only on software architectures. In Figure 6.1 we've listed four popular corporate software architectures. Most companies currently endorse, by a variety of different names, one of the software architectures listed in the left-hand box within the overall corporate software architecture space. Thus, for example, a company with a major commitment to off-the-shelf, back office applications from SAP or PeopleSoft is committed to a client-server architecture, while a company that primarily relies on older mainframe applications is probably relying on some kind of data-flow architecture.

Figure...