Welcome to Java Ranch ad congratulations on your new book.
This topic and the tile is very interesting even at this age of agile world
Ironically , looks like most of us still not perfected the art of doing the Right software using methodologies
like Agile.In that sense this book has come out at the right time and hope you have lot of interesting ideas
in the book.
Most people are doing Agile, but are not agile (the word, not the process).
Merely going through the motions, the rituals, gives you nothing.
As you will read in Chapter 4, the essence of agility is the ability to respond quickly to changes in the business.
That is what I mean by being agile.
Most systems (with or without Agile) rely of some flavor of domain decomposing, as a result, the changes are by definition not in one place.
This means that when there is a change to the business, the changes are slow, painful, and expensive.
By encapsulating the volatile areas you contain the changes, which allows you to BE agile.
Whether or not you go through the Agile motions is irrelevant.