In this chapter we first set the scene by establishing the case for doing design, specifically visual design, at all. Because Microsoft's new vision for how visual design should work is somewhat different from the old-world view based around UML, we highlighted the three main pillars that support that vision—namely, model-driven development (MDD), domain-specific languages (DSL), and software factories.
Because the underlying technologies have also evolved over time, thereby influencing the kinds of design you'll produce, we also traced that evolution of concepts from the original object-oriented paradigm through components and distributed-components to the service-oriented architectures that represent the current wisdom. We did that for a very good reason—as a lead-in to the Application Designer, which lends itself to service-based application design.
Application Designer is the first in the "Whitehorse" set of Distributed System Designers, which also includes Logical Datacenter Designer, System Designer, and Deployment Designer. We introduced each one and showed the important relationships between them. We also introduced Class Designer, which is not strictly part of the same set but which is complementary—and similar—in use.
Because all of the designers apart from Class Designer are tied together by a meta-model in the form of the System Definition Model (SDM), we introduced the term SDM and invited you to refer to Chapter 7 for further information.
We'd be failing you if we had not paid some attention to the hitherto industry-standard notation for visual modeling (UML). Our aim was not to compare the UML approach with Microsoft's vision, but to help you make the transition by suggesting which skills and artifacts might be transferable. Because Visual Studio doesn't yet provide a complete end-to-end modeling solution, you learned how you might continue to use Visio for Enterprise Architects in the early phases of the software development life cycle.
Having introduced the new visual designers in this chapter, we now devote Chapters 2 through 5 to covering them in detail.