Preface

—Benjamin Franklin

It has been a decade since the publication of the second edition of this book. During that time, the field of software architecture has broadened its focus from being primarily internally oriented—How does one design, evaluate, and document software?—to including external impacts as well—a deeper understanding of the influences on architectures and a deeper understanding of the impact architectures have on the life cycle, organizations, and management.

The past ten years have also seen dramatic changes in the types of systems being constructed. Large data, social media, and the cloud are all areas that, at most, were embryonic ten years ago and now are not only mature but extremely influential.

We listened to some of the criticisms of the previous editions and have included much more material on patterns, reorganized the material on quality attributes, and made interoperability a quality attribute worthy of its own chapter. We also provide guidance about how you can generate scenarios and tactics for your own favorite quality attributes.

To accommodate this plethora of new material, we had to make difficult choices. In particular, this edition of the book does not include extended case studies as the prior editions did. This decision also reflects the maturing of the field, in the sense that case studies about the choices made in software architectures are more prevalent than they were ten years ago, and they are less necessary to convince readers of the importance of software architecture. The case studies from the first two editions are available, however, on the book’s website, at www.informit.com/title/9780321815736. In addition, on the same website, we have slides that will assist instructors in presenting this material.

We have thoroughly reworked many of the topics covered in this edition. In particular, we realize that the methods we present—for architecture design, analysis, and documentation—are one version of how to achieve a particular goal, but there are others. This led us to separate the methods that we present in detail from their underlying theory. We now present the theory first with specific methods given as illustrations of possible realizations of the theories. The new topics in this edition include architecture-centric project management; architecture competence; requirements modeling and analysis; Agile methods; implementation and testing; the cloud; and the edge.

As with the prior editions, we firmly believe that the topics are best discussed in either reading groups or in classroom settings, and to that end we have included a collection of discussion questions at the end of each chapter. Most of these questions are open-ended, with no absolute right or wrong answers, so you, as a reader, should emphasize how you justify your answer rather than just answer the question itself.