Introduction to Process for System Architecture and Requirements Engineering
1.1. Purpose and Scope
The overall purpose of this book is to present a broad approach to the effective development of systems, especially those involving multiple disciplines—as most systems do. We use a variety of practical, real-world case studies to illustrate the nature of systems and the system development process, and we include system models that can be used in the process.
The book builds on the methods and techniques originally described in Strategies for Real-Time System Specification [Hatley 88]. It is based on more than a decade of experience, our own and many others’, in the practical application and teaching of the methods and techniques. When Strategies was written, we were working in the avionics engineering field, but since then, we have helped to introduce the methods, and have taught and facilitated their use, on a wide variety of projects, ranging from communications systems to biomedical systems, and from three-person projects to those of a hundred people and more.
The wide acceptance of the methods—which became known as the Hatley/Pirbhai methods—has been gratifying, but not all practitioners have used them correctly or effectively. There have been several changes over the years in the methods and their use, and several CASE (computer-aided system/software engineering) tool developers have sought to automate the methods. Besides a few notable exceptions, most of these tools have fallen far short of doing the job adequately. Our goal, then, is to share the benefit of our experiences, good and bad, in the hope of improving the overall state of system development and the methods and tools that support it.