Much of this book is concerned with various models. (As we said earlier, a model is an abstraction used to simplify or represent a process or concept.) It is important to remember that many of these models are interrelated. As we conclude Part 1 of this book, we need to examine the relationships between models at three different layers of abstraction.
The MSF Enterprise Architecture Model discussed in Chapter 1 should exist at the highest level of abstraction within the IT environment. In other words, it is the top-level model or artifact for IT design and practice. It should be related to, and driven by, the organization's strategic plan. In turn, the MSF Enterprise Architecture Model should be the driver for any Enterprise Application Models that are developed.
The information captured in a higher-level model or document should inform and flow into the appropriate area of the lower-level model or document. The plans and processes outlined in the organization's strategic plan and operations manual should, for example, be the basis for the Business Perspective of the MSF Enterprise Architecture Model. In turn, the Business Perspective of the MSF Enterprise Architecture Model should form the Business Model of specific enterprise applications. In other words, each application's architecture must also cohabit with the organization's enterprise architecture.
In this chapter, we discussed the MSF Development Process Model, which describes the process for building an application. A part of this model is the development of a Design Model for the application's conceptual, logical, and a physical architecture. Although it is not a step-by-step process, the MSF Development Process Model helps provide the steps for a project team to get where it wants to go.
It is sometimes difficult to show a clear-cut information flow between parts of one model and parts of another.
It is also important to clearly understand terms from different models that are similarly named. Table 4.3 helps keep the terms in their correct "home" model.
Table 4.3 Related terms from different models
|MSF Enterprise Architecture Model||Enterprise Application Model||MSF Design Model|
|Business Perspective||Business Model||Conceptual Design|
|Technology Perspective||Technology Model|
|Logical Model||Logical Design|
|Physical Model||Physical Design|