 providers) that kindly agreed to participate in the interviews conducted in the frame of the project; these interviews provided an invaluable insight into the processes ongoing in the OSS/BSS software market today. We would also like to thank the other organizations that provided complementary (quantitative and qualitative) data for this research: Dittberner Associates; Forrester Research; TeleManagement Forum. We wish to express our gratitude to the international experts with whom fruitful seminars and workshops were held on various topics considered in the project, in particular to professor Jeffrey Funk (National University of Singapore), with whom the issues of industry (and technology) evolution were discussed, and to professor Hong-Mei Chen and professor Rick Kazman (University of Hawaii and Carnegie Mellon/SEI) for the collaboration on the topics of software architecture evaluation and service orientation in telecom industry. We also greatly appreciate the help of Steve Legrand in improving the language of the manuscript. Preface The telecom operator software market (OSS/BSS market) is analyzed in this book from the viewpoints of the business processes reflecting the telecom business, from the technology viewpoint visible in OSS/BSS interfaces, and from the market viewpoint as presented in market statistics. Chapter 1 presents the scientific back- ground and Chapters 2 and 3 present a detailed analysis. The results have been condensed in Section 4.2 from the business perspective. It presents a default scenario containing both the main past events impacting the OSS/BSS markets and the expected future evolution of this vertical software market, which is created by matching the available market data against the model of vertical software industry evolution and other theories presented. Section 4.3 describes the method used, which can also be applied for other vertical software markets. This preface outlines the main results for the OSS/BSS market from the business perspective. The OSS/BSS market is exception