Introduction

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More years ago than I care to remember, let us say twenty five to thirty, Software Metrics was a curiosity confined to a few university researchers and one or two industrial or commercial organizations. Now it is a well established discipline with a growing band of practitioners and adherents. Indeed there is now a whole train of theory and practice that is called "Software Metrics." But, I suggest, still the train moves too slowly. This book is an attempt to speed the train up by helping you to add momentum. Having said that, things have progressed enormously from that dim and distant past!

Today, it seems you cannot attend any software engineering conference or seminar without coming across at least one speaker who features the subject Software Metrics. We can find active user groups specializing in particular applications within the general domain of Software Metrics; there are research projects funded by the European Economic Community involving some of the largest industrial organizations in the world; and, there are specialist international conferences and workshops that attract large audiences on a regular basis.

However, despite the huge increase of interest in the use of Software Metrics within industry (and I include all types of commercial and engineering applications in the term "industry"), much of what we see is to do with the definition of particular techniques. One of the problems facing the IT industry today is the application of these techniques in a business environment. Little has been written about solving the very practical problems faced by organizations who wish to introduce the use of Software Metrics, and another aim of this book is to go some way towards correcting that.

The material in the book is based on many years of experience in implementing Software Metrics initiatives, four of them as a direct employee in two large organizations. This has been enhanced by experiences gained from acting in a consultancy role to a number of other organizations engaged in implementing similar programs over many more years. The suggestions and models presented in the text are the result of having to find pragmatic solutions to very real, business related problems.

I do not claim that this book is the last word that will ever need to be said about the topic of implementing Software Metrics initiatives; it is not. What it does contain are a set of approaches and techniques, presented as a coherent whole, that have worked in those real business situations together with discussions about specific aspects of Software Metrics based on those same experiences.

Nor can I claim that all of the components that make up this book are my own. I have been privileged to meet some very talented people in many organizations across the world who have been willing to share ideas and concepts freely so that everyone benefits. For this I thank them and I have provided references to their work, whenever I could, throughout the body of this book.

This has not just been a sharing of successes, but also of failures and frustrations. I am able to contribute very easily when it comes to failures! I believe that one of the things this work has to recommend it is that it is based, in part, on learning from those failures and the hope is that the reader can avoid the mistakes that I and others have made in the past.

Interestingly, I have found that there are great similarities in the mistakes we have made and also in the successes we have had. It is this that makes me feel that a book like this, which attempts to illustrate a generic approach to the implementation of Software Metrics programs, can work.

Turning from the background to the book itself, I hope that you find it to be readable. To help in this, the material has been separated into three sections.

The first defines exactly what I mean by the term "Software Metrics" and introduces the reader to the domain of Software Metrics by discussing the need for a measurement-based approach to the management of software engineering. This first section then, for reasons which will become obvious, looks at a particular measurement technique—Function Point Analysis—before discussing specific areas of application for Software Metrics.

The second section is really the core of the book. This section describes an approach to the development and implementation of Software Metrics initiatives. Essentially, the approach centers around a model that breaks the work into a number of stages. This division of labor into phases is, of course, nothing more than the way in which most successful projects are handled; it is what makes up those stages that I hope will be found beneficial.

The third section is a collection of chapters that belong in this book, but do not sit naturally in either of the other two sections. Here we visit the topics that seem to be generating discussion today and we will also look at some topics that may be key issues in the near future.

Appendices and references are also provided.

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