book describes two methods for specifying, respectively, the requirements for
and the design structure of software based systems. Although the methods grew
up around real-time embedded systems, systems of all-types and sizes have benefits
from them, largely because of their flexibility and adaptability. The methods
can be viewed as an integrated toolkit from which all the tools are compatible,
but only those that are useful for the particular job need be used.
subject of this book is neither computer science nor software. Although the vast
majority of the systems to which methods are applied will in fact be implemented
using software in digital computers, the methods do not address how to write that
software or how to design tat hardware. What the methods do is address is how
to specify the problems that the hardware and software must solve.
and audience of the book
The book is intended for a wide range of readers/
We assume that you are involved, or at least interested, in software-based systems,
but that your needs may range from just a general understanding to an in-depth
working knowledge. We have tried to organize the book to make it easy for you
to select those parts that are of specific interest to you and to avoid those
that are not.
The figure following shows the layout of the book. Part I
provides an overview from which everyone will benefit. Parts II and IV describe
what the methods are, and if you only need to understand the specifications
resulting from their use, then these two parts are enough for you to read. If
you need to prepare specifications, then you will also need to read Parts
II and V, which describe how to use the methods. Part VI contains examples
of the application of the methods, and we conclude the book with the appendices
and a brief reference list.
A Map of the Book
Decide what your area of
interest isrequirements analysis, design, or bothand what depth of
understanding you needgeneral familiarity, use of the completed specifications,
or building the specificationsand it will be clear from the figure which
parts of the book you should read.