Pattern-Oriented Software Architecture For Dummies

Examining UML Architectural Models

You can visualize and explain an architecture in many ways. The most common approach in use today is the Unified Modeling Language, or UML for short. In this section, I provide an overview of how UML is used to illustrate software architectures.

Choosing a diagram style

UML has many specific symbols and conventions. I won't tell you about all of them, because you can find books related to the topic, such as UML 2 For Dummies, by Michael Jesse Chonoles and James A. Schardt (Wiley).

Here are a few of the diagram styles that I find most useful for describing architectures:

• Class
• Interaction
• Deployment
• Packaging
• Use case

In the next section, I tell you when I use each of these diagram styles. Later in this chapter, in the section “Explaining Your Software in an Architecture Document,” I provide detailed information about using diagrams in your documentation.

Showing different views

You create diagrams to explain the software architecture to your team members, colleagues, and management and to help you remember what you've designed with the types of UML diagrams just mentioned. These diagrams fit into the 4 + 1 model that I describe in Chapter 1 and that you see in Figure 3-1, which shows the types of UML diagrams that are best suited to the different views.

The following sections discuss the correlations between the views and the diagram types.

Figure 3-1: The 4 + 1 model with UML styles.

Logical view

When you want to show how individual classes ...