Reusing Open Source Code: Value Creation and Value Appropriation Perspectives on Knowledge Reuse

305 Pages·2011·2.76 MB·English

by  Manuel Sojer (auth.)

Manuel Sojer
Reusing Open Source Code
GABLER RESEARCH
Innovation und Entrepreneurship

Herausgegeben von
Professor Dr. Nikolaus Franke,
Wirtschaftsuniversität Wien,
Professor Dietmar Harhoff, Ph.D.,
Universität München, und
Professor Dr. Joachim Henkel,
Technische Universität München
Innovative Konzepte und unternehmerische Leistungen sind für Wohlstand und
Fortschritt von entscheidender Bedeutung. Diese Schriftenreihe vereint wissen-
schaftliche Arbeiten zu diesem Themenbereich. Sie beschreiben substanzielle
Erkenntnisse auf hohem methodischen Niveau.
Manuel Sojer
Reusing Open Source Code

Value Creation and Value Appropriation
Perspectives on Knowledge Reuse
With a Foreword by Univ.-Prof. Dr. Joachim Henkel
RESEARCH
Bibliographic information published by the Deutsche Nationalbibliothek
The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografi e;
detailed bibliographic data are available in the Internet at http://dnb.d-nb.de.
Dissertation Technische Universität München, 2010

1st Edition 2011
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Preface
Over the past decade, open source software (OSS) has attracted enormous interest from
practitioners and academics alike. However, the focus of research on OSS is mostly on
individuals’ and firms’ contributions to public OSS projects. In contrast, the receiving side
of this open and collaborative development process has been given much less attention,
despite indications that the reuse of OSS code is of high importance in the development of
both OSS and of proprietary software. Questions regarding quantity, motivation, and
drivers of OSS code reuse have been studied only by few authors, and in no case
quantitatively. In particular, the role of individual programmers in the context of “ad hoc”
code reuse and concomitant legal risks are largely unexplored.
Manuel Sojer addresses the above issues in this ground-breaking book. After
developing the theoretical foundations of his work, he presents two large-scale empirical
studies on the reuse of publicly available OSS code. Both studies are based on carefully
constructed models that draw on the Theory of Planned Behavior. Focusing on the amount
of code reuse that programmers practice in public OSS projects, the first survey yields
highly interesting findings regarding the drivers of and impediments to reuse in this setting,
with important conclusion to be drawn for code reuse within firms.
The second survey complements the first one by addressing the reuse of OSS and
similar code in proprietary software development. In particular, with its focus on license
risks this study takes a value appropriation rather than value creation perspective. Using an
elaborate survey design, the author derives important results regarding the determinants of
negligent or even deliberate violation of license obligations by employed programmers. As
the first one, this study bears obvious significant implications for academics as for
managers.
This book is Manuel Sojer’s doctoral thesis at Technische Universität München. It is
full of good ideas, flawless analyses, and novel findings, and I strongly recommend it to
practitioners and academics alike. It was a pleasure to be Manuel Sojer’s thesis advisor.

Prof. Dr. Joachim Henkel
Foreword
The reuse of existing knowledge is of crucial importance in innovation processes in
general and particularly so in software development. In my dissertation I investigate this
phenomenon from the perspective of individual software developers and research their
reuse of open source code. In this context I analyze, on the one hand, the factors which
influence the extent to which software developers reuse existing knowledge in the form of
code and thereby increase the value creation of their firms. On the other hand, I investigate
potential value appropriation risks for firms which may result from the reuse of existing
knowledge in the form of code from the internet (such as open source code) through their
software developers.
Throughout my dissertation work I have received both advice and support from many
people. I want to take this opportunity to express my gratitude to all those who have helped
me along the way.
First of all, I am indebted to my thesis advisor Prof. Dr. Joachim Henkel for his
continuous support of my work, his valuable suggestions and comments regarding my
research, his approachability and responsiveness at all times and his contagious fascination
for interesting research questions. I am also grateful to my second advisor Prof. Dr. Isabell
Welpe and to Prof. Dr. Christoph Kaserer who chaired my dissertation committee.
The empirical approach of my dissertation would not have been possible without the
more than 50 industry experts and software developers who made themselves available for
interviews, as well as the roughly 2,000 participants in the two surveys I conducted. I am
indebted to all of them for their valuable thoughts and their time.
I am also grateful to my colleagues Oliver Alexy, Jörn Block, Annika Bock, Timo
Fischer, Florian Jell, Stefanie Pangerl, Anja Schön, Frank Spiegel, Johannes Wechsler and
Evelin Winands for the pleasant and inspiring atmosphere at the Schöller Chair in
Technology and Innovation Management. Particular thanks go to Oliver Alexy, Timo
Fischer and Johannes Wechsler for their comments and suggestions regarding both content
and methodology of my work.
Moreover, I owe thanks to my dear friend Werner Skalla for diligently reading and
commenting my manuscript. I am also grateful to Michael Maier for the various activities
with which he supported me as a student assistant during his time at the Schöller Chair of
Technology and Innovation Management.
VIII Foreword

Finally, I am indebted to my girlfriend Maria for her continuous encouragement, her
optimism and her thoughtfulness, put in one word, for her companionship along the way.
Above all, I thank my parents and my brother for always and unconditionally providing me
with a safe harbor. My parents have nurtured my education from the very beginning and
have always supported me on my way. In doing so they have laid the foundations for this
dissertation which I dedicate to them.

Manuel Sojer
Table of Contents
Table of Contents...............................................................................................................IX
List of Figures................................................................................................................XIII
List of Tables...................................................................................................................XIV
List of Abbreviations.......................................................................................................XV
Zusammenfassung........................................................................................................XVII
Abstract...........................................................................................................................XXI
1. Introduction.....................................................................................................................1
1.1. Motivation: The Cisco/Linksys case.......................................................................2
1.2. Research objectives.................................................................................................3
1.3. Structure of the dissertation.....................................................................................8
2. Foundations of value creation and value appropriation.............................................9
2.1. Concepts and terminology.....................................................................................10
2.2. Determinants of value creation..............................................................................14
2.3. Determinants of value appropriation.....................................................................15
2.4. Summary................................................................................................................18
3. Open source software developers’ perspectives on code reuse.................................20
3.1. Introduction...........................................................................................................20
3.2. Foundations of knowledge reuse...........................................................................23
3.2.1. Knowledge reuse to create value...............................................................23
3.2.2. Knowledge reuse in software development...............................................26
3.2.3. The not-invented-here syndrome...............................................................33
3.2.4. Intermediate conclusion.............................................................................35
3.3. OSS and its development.......................................................................................36
3.3.1. History of OSS..........................................................................................37
3.3.2. OSS licenses..............................................................................................39
3.3.3. OSS development......................................................................................40
3.3.4. Motivations of OSS developers.................................................................45
3.3.5. Code reuse in OSS development...............................................................50
3.3.6. Intermediate conclusion and detailed research questions..........................53
3.4. Research model and hypotheses............................................................................54
3.4.1. The theory of planned behavior.................................................................55
3.4.2. Qualitative pre-study.................................................................................56
3.4.3. Determinants of code reuse behavior........................................................57
X Table of Contents

3.5. Survey design and methodology...........................................................................72
3.5.1. Data source and sample selection..............................................................72
3.5.2. Survey design............................................................................................75
3.5.3. Pretest........................................................................................................77
3.5.4. Conducting the survey...............................................................................77
3.6. Descriptive and exploratory analyses....................................................................79
3.6.1. Survey participants and their OSS projects...............................................80
3.6.2. Importance and extent of code reuse.........................................................86
3.6.3. Developers’ reasons for and against code reuse........................................90
3.6.4. Component and snippet reuse....................................................................99
3.6.5. Developers’ sources to search for existing code to reuse........................105
3.6.6. Summary..................................................................................................108
3.7. Multivariate analysis of determinants of code reuse...........................................110
3.7.1. Hypotheses..............................................................................................110
3.7.2. Variables..................................................................................................111
3.7.3. Statistical methods used..........................................................................115
3.7.4. Results.....................................................................................................115
3.7.5. Discussion and summary.........................................................................122
3.8. Conclusion...........................................................................................................126
4. Commercial software developers’ perspectives on internet code reuse.................131
4.1. Introduction.........................................................................................................131
4.2. Foundations of internet code reuse in commercial software development..........135
4.2.1. Obligations from internet code reuse.......................................................135
4.2.2. Internet code reuse in commercial software development......................141
4.2.3. Intermediate conclusion and detailed research questions........................145
4.3. Research model and hypotheses..........................................................................148
4.3.1. Theoretical models to predict ethical behavior........................................149
4.3.2. Qualitative pre-study...............................................................................150
4.3.3. Determinants of violations of internet code reuse obligations................152
4.4. Survey design and methodology.........................................................................168
4.4.1. Data source and sample selection............................................................168
4.4.2. Survey design..........................................................................................169
4.4.3. Pretest......................................................................................................173
4.4.4. Conducting the survey.............................................................................173
4.5. Descriptive and exploratory analyses..................................................................176
4.5.1. Survey participants and their firms..........................................................176
4.5.2. Developer awareness of internet code reuse obligations.........................180
4.5.3. Internet code reuse in commercial software development......................186
4.5.4. Extent of (potential) violations of internet code obligations...................191
4.5.5. Summary..................................................................................................193
Table of Contents XI

4.6. Research model testing and results......................................................................195
4.6.1. Hypotheses..............................................................................................195
4.6.2. Statistical methods used..........................................................................196
4.6.3. Measurement model assessment and descriptive statistics......................198
4.6.4. Structural model assessment....................................................................208
4.6.5. Discussion and summary.........................................................................212
4.7. Conclusion...........................................................................................................217
5. Conclusion...................................................................................................................228
Appendix...........................................................................................................................237
A.1. Code reuse in open source software development...............................................238
A.2. Code reuse in commercial software development...............................................250
Bibliography.....................................................................................................................263