Changes for the Second Edition

As the UML evolved, and I received feedback about the first edition of the book, I continually updated it. We reprinted every two or three months; nearly every printing contained updates, which resulted in considerable strain on the processes of the publishing industry.

With the change from UML 1.2 to 1.3, we decided to do a more thorough overhaul of the book, enough to produce a second edition. Since the book has been so popular, I've tried not to change the essential spirit of the book. I've carefully tried to not add much, and to see whether there are things I can take away.

The biggest changes are in Chapter 3, about use cases, and Chapter 9, about activity diagrams, which have each received a severe rewrite. I've also added a section on collaborations to Chapter 7. Elsewhere, I've taken the opportunity to make a host of smaller changes, based on feedback and my experiences over the last couple of years .