Theme Process Overview

Now that you have a sense of what a theme is and how it looks at requirements analysis and design, we delve into how to get from a set of requirements to a set of modeled themes. This chapter provides a high-level glance at this process. The rest of the book goes into the process in far more detail.

The Theme approach helps you to identify and model themes. The approach also helps you identify which of those themes are crosscutting themes and which are not. The approach involves two representations: Theme/Doc, which is used for viewing and analyzing requirements, and Theme/UML, which is applied for design. Using Theme/Doc, you view the relationships between concepts described in a set of requirements and refine the concepts into features, or themes. You then apply Theme/UML to design the themes and to designate how shared structure and behavior should be recombined. You perform three main activities when applying the approach: analysis, design, and composition. The activities are depicted in Figure 3-2 and are described at a high level in the list below.

1. Analysis. The first step in the approach is to perform analysis of the requirements to identify themes. This involves mapping requirements to concerns in the system. Theme/Doc lets you view the relationships between behaviors. These relationships expose tangled concerns and lead you to identifying aspects.

2. Design. You then design the themes using Theme/UML. Use the themes you found using Theme/Doc to identify potential classes and methods, then fill in the design details and make changes that are needed to benefit the design. Other aspect themes are likely to emerge during detailed technical design.

3. Composition. You then specify how the Theme/UML models should be recombined. In many cases, some of the Theme/Doc views will help to determine how themes relate to one another: whether they overlap or whether they crosscut one another.

Figure 3-2. Theme process.

You'll notice that some of the arrows shown in Figure 3-2 are styled "automatic." These arrows depict actions that the Theme toolkit performs automatically. The Theme/Doc tool generates views of requirements and themes and their relationships. The Theme/UML tool allows design composition based on Theme/UML composition relationships.

For the rest of this chapter, we work through each activity in more depth, using the EES from Chapter 2 as an example. Later, Chapters 4, 5, and 6 go into greater detail on a more involved example.