The authors of this book are both practicing software architects who have worked in this role, together and separately, on information system development projects for quite a few years. During that time, we have seen a significant increase in the visibility of software architects and in the importance with which our role has been viewed by colleagues, management, and customers. No large software development project nowadays would expect to go ahead without an architect—or a small architectural group—in the vanguard of the development team.

While there may be an emerging consensus that the software architect’s role is an important one, there seems to be little agreement on what the job actually involves. Who are our clients? To whom are we accountable? What are we expected to deliver? What is our involvement once the architectural design has been completed? And, perhaps most fundamentally, where are the boundaries between requirements, architecture, and design?

The absence of a clear definition of the role is all the more problematic because of the seriousness of the problems that today’s software projects (and specifically, their architects) have to resolve.