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Governance Structures of Free/Open Source Software Development

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Governance Structures of Free/Open Source Software Development Uitnodiging GOVERNANCE STRUCTURES OF FREE/OPEN 51 SOURCE SOFTWARE DEVELOPMENT Voor het bijwonen van de George Dafermos openbare verdediging van het Modularity theory makes a compelling argument: modular product design increases the potential number of persons that could work on a distributed project and has a positive effect proefschrift: on their labour productivity because it allows them to work independently of each other, with little or no need for central coordination. This doctoral dissertation sets out to put this argument to the test by studying a phenomenon that combines both scale and modularity: Governance Structures Free and open source software (FOSS) development. Its central question is: Does modularity mitigate the adverse effects of increasing scale in FOSS development? of Free/Open Source Software Development In exploring the effect of modularity and increasing scale on the dynamic of development of FreeBSD, a large and well-known FOSS project, over a period of fifteen years, the dissertation addresses several related empirical issues: How are FOSS projects organised? How are they governed? And most interestingly, how do they manage increasing scale? Does their ability to self-organise diminish as they grow larger, thereby necessitating hierarchical coordination? Op maandag 10 december 2012 om 15 uur precies in de Frans Source Software Development Source Software Governance Structures of Free/Open van Hasseltzaal van de Aula van de Technische Universiteit Delft, Mekelweg 5 te Delft The Next Generation Infrastructures Foundation George Dafermos represents an international consortium of knowledge institutions, market players and governmental bodies, which joined forces to cope with the challenges faced Governance Structures by today’s and tomorrow’s infrastructure systems. The consortium cuts across infrastructure sectors, across discplinary borders and across national borders, of Free/Open Source as infrastructure systems themselves do. With the strong participation of Software Development practitioners in a concerted knowledge effort with social and engineering scientists, Voorafgaand aan de verdediging the Foundation seeks to ensure the conditions for utilization of the research results geef ik om 14.30 een korte toelichting bij het proefschrift by infrastructure policy makers, regulators and the infrastructure industries. 51 www.nginfra.nl Direct na afloop is er ter plaatse een receptie George Dafermos Von Geusaustraat 130 2274RN Voorburg [email protected] GOVERNANCE STRUCTURES OF FREE/OPEN SOURCE SOFTWARE DEVELOPMENT examining the role of modular product design as a governance mechanism in the FreeBSD Project George DAFERMOS GOVERNANCE STRUCTURES OF FREE/OPEN SOURCE SOFTWARE DEVELOPMENT examining the role of modular product design as a governance mechanism in the FreeBSD Project PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Technische Universiteit Delft, op gezag van de Rector Magnificus prof. ir. K.C.A.M. Luyben, voorzitter van het College voor Promoties, in het openbaar te verdedigen op 10 december 2012 om 15.00 uur door George DAFERMOS Master of Science in Electronic Commerce Applications at University of Sunderland, England geboren te Irakleio, Griekenland. Dit proefschrift is goedgekeurd door de promotor: Prof.dr. M.J.G. van Eeten Samenstelling promotiecommissie: Rector Magnificus voorzitter Prof.dr. M.J.G. van Eeten Technische Universiteit Delft, promotor Prof.mr.dr. J.A. de Bruijn Technische Universiteit Delft Prof.dr. J.P.M. Groenewegen Technische Universiteit Delft Prof.dr. V.J.J.M. Bekkers Erasmus Universiteit Rotterdam Prof.dr. J.M. Bauer Michigan State University Dr. M. den Besten Montpellier Business School ISBN 978-90-79787-40-1 Published and distributed by: Next Generation Infrastructures Foundation P.O. Box 5015, 2600 GA Delft, the Netherlands [email protected], www.nginfra.nl This research was funded by the Next Generation Infrastructures Foundation programme and TU Delft. This work is licensed under the Creative Commons Attribution-Noncommercial- Share Alike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA. To the memory of my mother Contents Acknowledgements.....................................................................................xi Chapter Synopsis.......................................................................................xiii CHAPTER 1: INCREASING AND DECREASING RETURNS TO SCALE...........1 INTRODUCTION..............................................................................................1 INCREASING RETURNS TO SCALE: THE ADVANTAGES OF BIGNESS ...1 DECREASING RETURNS TO SCALE...............................................................6 Decreasing returns to scale due to coordination costs ................................6 Decreasing returns to scale due to reduced individual motivation ..........10 DOES PRODUCT MODULARITY MITIGATE THE ADVERSE EFFECTS OF INCREASING SCALE?.....................................................................................12 CHAPTER 2: LITERATURE REVIEW................................................................15 THE PRODUCTIVITY PARADOX IN SOFTWARE DEVELOPMENT .......15 MODULARITY IN ORGANISATION THEORY...........................................18 Product modularity and coordination costs...............................................22 Product modularity and productivity........................................................27 Product modularity and group size............................................................28 STUDYING MODULARITY IN FREE AND OPEN SOURCE SOFTWARE DEVELOPMENT ............................................................................................30 H1: Product modularity reduces coordination costs in FOSS projects......34 H2: Product modularity increases the potential number of contributors to FOSS projects..............................................................................................37 H3: Product modularity has a positive effect on labour productivity in FOSS projects..............................................................................................40 CONCLUDING REMARKS.............................................................................41 CHAPTER 3: RESEARCH METHODOLOGY.....................................................43 ANALYTICAL FRAMEWORK.......................................................................43 Research Design..........................................................................................43 Object of investigation................................................................................44 Level of analysis..........................................................................................46 WHY THE FREEBSD PROJECT?....................................................................47 MEASURING MODULARITY........................................................................48 MEASURING COORDINATION COSTS.......................................................55 MEASURING DEVELOPERS GROUP SIZE..................................................59 vii MEASURING LABOUR PRODUCTIVITY.....................................................63 STATISTICAL ANALYSIS...............................................................................65 Sample selection..........................................................................................66 Random-effects GLS regression..................................................................67 Operationalisation.......................................................................................69 CHAPTER 4: EMPIRICAL SETTING..................................................................75 HISTORICAL BACKGROUND.......................................................................75 ORGANISATIONAL STRUCTURE................................................................78 Core team....................................................................................................79 Committers..................................................................................................82 Outside contributors...................................................................................84 Ad hoc teams...............................................................................................84 Hats..............................................................................................................86 Maintainers.................................................................................................86 TECHNICAL INFRASTRUCTURE.................................................................87 Communication channels...........................................................................87 Revision control .........................................................................................88 Reporting & managing defects...................................................................88 Testing.........................................................................................................88 Distribution channels.................................................................................89 DEVELOPMENT PROCESS ...........................................................................89 SCALE .............................................................................................................91 CHAPTER 5: MODULARITY
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