The foundation of any software system is its architecture, this text is intended to help architects determine what aspects of their architectures need improvement. The techniques put forward are based on actual practice in both government and industry development organizations.
Praise for Evaluating Software Architectures
“The architecture of complex software or systems is a collection of hard decisions that are very expensive to change. Successful product development and evolution depend on making the right architectural choices. Can you afford not to identify and not to evaluate these choices? The authors of this book are experts in software architecture and its evaluation. They collected a wealth of ideas and experience in a well-organized and accessible form. If you are involved in the development of complex systems or software, you will find this book an invaluable guide for establishing and improving architecture evaluation practice in your organization.”
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Alexander Ran, Principal Scientist of Software Architecture, Nokia
“Software engineers must own this book. It is a well-written guide to the steps for evaluating software architecture. It argues for the inclusion of architecture evaluation and review as a standard part of the software development lifecycle. It introduces some new and innovative methods for analyzing important architecture characteristics, like extensibility, portability, and reliability. I believe these methods will become new engineering cornerstones for creating good software systems.”
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Joe Maranzano, AT&T Bell Labs Fellow in Software Architecture (1990), and former head of the Bell Labs Software Technology Center
“Experience and teamwork are the only approaches I know of to deliver products faster, cheaper, and yet to delight your customers. In their first book, Software Architecture in Practice, Paul and Rick (and Len Bass) helped me match my experience with theory. Their invaluable approaches and case studies changed my practice and the way I proceed to design systems and software architectures. This second book, with Mark, covers what I will look at before I feel good about an architecture. It is about how I can tap other people's experience to produce an improved outcome, using other people's feedback. I have used many of the concepts explained in this book for my customers' benefit. Using this book, you—architects, developers, and managers—will develop a common language and practice to team up and deliver more successful products.”
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Bertrand Salle, lead architect with a major telecommunications company
“If architecture is the foundation of system construction, architectural evaluation is part of the foundation of getting to a ‘good’ architecture. In this book, the authors put their considerable expertise to one of the most pressing issues in systems development today: how to evaluate an architecture prior to system construction to ascertain its feasibility and suitability to the system of interest. The book provides a practical guide to architecture evaluation using three contemporary evaluation methods. It should prove valuable to practitioners and as a basis for the evolution of architectural evaluation as an engineering practice.”
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Rich Hilliard, Chief Technical Officer, ConsentCache, Inc., and technical editor,
IEEE Recommended Practice for Architectural Description of Software-Intensive Systems “Too many systems have performance and other problems caused by an inappropriate architecture. Thus problems are introduced early, but are usually detected too late—when the deadline is near or, even worse, after the problem makes the headlines. Remedies lead to missed schedules, cost overruns, missed market windows, damaged customer relations, and many other difficulties. It is easy to prevent these problems by evaluating the architecture choices early, and selecting an appropriate one.”
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Connie U. Smith, Ph.D., principal consultant, Performance Engineering Services Division, L&S Computer Technology, Inc., and coauthor of the new book,
Performance Solutions: A Practical Guide to Creating Responsive, Scalable Software “The ATAM an evaluation method described in this book is the natural quality-gate through which a high-level design should pass before a detail design project is initiated. Why use the ATAM to evaluate an architecture? Mitigation of design risk is a major reason, but more importantly, the ATAM provides an interactive vehicle that can give key development and user stakeholders architectural visibility—visibility that can lead to an important ‘early buy-in.’”
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Rich Zebrowski, Software Technology Manager, Motorola, Inc.
“Caterpillar's experience with architecture reviews includes SAAM, ATAM, ARID, and ADR evaluation methods described in this book, the first three in detail. These reviews ensured that the needs of the user community were being met, and they exposed the architecture to others in the organization helping with understanding and organizational buy-in. The SAAM- and ATAM-based evaluations worked well to expose the architecture early in the development cycle to a broad range of people. The ARID- and ADR-based evaluations facilitated the exposure of technical details of the architecture later in the development cycle. As the architect of the pilot project for ARID, I observed that this review even served as an architecture training session before the architecture was fully documented.”
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Lee R. DenBraber, former Lead Software Architect, Caterpillar, Inc.
“We’ve heard all the management hype about harnessing the innovative creativity of our teams, establishing integrated customer-developer-product teams, and better targeting our systems to meet end user needs. The ATAM techniques described in this book give technical managers, system architects, and engineers proven tools for breaking down the communications barriers that impede our ability to realize these goals. We have successfully integrated the ATAM techniques throughout our lifecycle, including development and maintenance, and have found that they provide the strong technical basis we need to evaluate the many difficult trades required by a system as large as EOSDIS.”
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Mike Moore, Deputy Manager, Science Systems Development Office, Earth Observing System Data Information System (EOSDIS) Project, NASA Goddard Space Flight Center
“If you know how difficult architecture reviews are, you will be amazed how effective ATAM evaluations can be. For example, an ATAM evaluation we conducted on an important software product line identified a major architectural risk, which we subsequently were able to avoid-a benefit we expect to continue seeing. Moreover, ATAM techniques have enabled us to explain such risks to stakeholders far more clearly than by any other review method.”
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Stefan Ferber, Corporate Research, Robert Bosch GmbH
Drawing on clearly identified connections between architecture design decisions and resulting software properties, this book describes systematic methods for evaluating software architectures and applies them to real-life cases. It shows you how such evaluation can substantially reduce risk while adding remarkably little expense and time to the development effort (in most cases, no more than a few days). Evaluating Software Architectures introduces the conceptual background for architecture evaluation and provides a step-by-step guide to the process based on numerous evaluations performed in government and industry.
In particular, the book presents three important evaluation methods:
- Architecture Tradeoff Analysis Method (ATAM)
- Software Architecture Analysis Method (SAAM)
- Active Reviews for Intermediate Designs (ARID)
Detailed case studies demonstrate the value and practical application of these methods to real-world systems, and sidebars throughout the book provide interesting background and hands-on tips from the trenches.
All software engineers should know how to carry out software architecture evaluations. Evaluating Software Architectures is the chance to get up to speed quickly by learning from the experience of others.
