In this part, I propose an approach to designing object-oriented systems based on patterns. I have proven this approach in my own design practice. I apply this approach to the CAD/CAM problem that we have been examining since Chapter 3, “A Problem That Cries Out for Flexible Code.”
This approach first tries to understand the context in which objects show up. Although this approach is limited in application, it sets the stage for the more general approach that I propose in the next part of the book.