Pattern-Oriented Software Architecture For Dummies

Selecting a Particular Pattern

Now that you know how to evaluate patterns (see the previous section), you're ready to start searching for and selecting patterns. You can find patterns in many places, such as in this book, in other books of collected patterns, in magazines such as IEEE Software and Dr. Dobbs, in technical conference papers, and on the Internet. As you develop your personal pattern catalog (see Chapter 7), you'll discover sources for the patterns that are most relevant to your work.

Figure 8-1 shows a seven-step method for selecting a pattern for use in a design. I explain this method in detail in the following sections.

Figure 8-1: Seven steps to selecting a pattern.

Step 1: Specify the problem

The first step in finding a pattern is identifying the problem that you want to solve. The problem needs to be concrete like “securing a three-tier architecture,” rather than something general like “making a website.”

Splitting your problem into sub-problems

If the problem seems to have several parts, split the problem into smaller sub-problems, such as “managing the user interface” and “setting up the back-end database.” Sometimes, the sub-problems aren't related to the structure but are related to the nonfunctional requirements — for example, if you need to design a web service that behaves in a certain way and the solution needs to be highly available. Divide this problem ...