Sebastian Heil Web Migration Revisited: Addressing Effort and Risk Concerns Doctoral Dissertations in Web Engineering and Web Science Volume 5 Prof. Dr.-Ing. Martin Gaedke (Series Editor) Sebastian Heil Web Migration Revisited Addressing Effort and Risk Concerns Universitätsverlag Chemnitz 2021 Impressum Bibliografische Information der Deutschen Nationalbibliothek Die Deutsche Nationalbibliothek verzeichnet diese Publikation in der Deutschen Nationalbibliografie; detaillierte bibliografische Angaben sind im Internet über https://www.dnb.de abrufbar. Das Werk - ausgenommen Zitate, Cover, Logo TU Chemnitz und Bildmaterial im Text - steht unter der Creative-Commons-Lizenz Namensnennung 4.0 International (CC BY 4.0) https://creativecommons.org/licences/by/4.0/deed.de Titelgrafik: Sebastian Heil Satz/Layout: Sebastian Heil Technische Universität Chemnitz/Universitätsbibliothek Universitätsverlag Chemnitz 09107 Chemnitz https://www.tu-chemnitz.de/ub/univerlag readbox unipress in der readbox publishing GmbH Rheinische Straße 171 44147 Dortmund https://www.readbox.net/unipress/ ISSN 2199-5354 print - ISSN 2199-5362 online ISBN 978-3-96100-125-5 https://nbn-resolving.org/urn:nbn:de:bsz:ch1-qucosa2-723455 Faculty of Computer Science Distributed and Self-Organizing Systems Group Web Migration Revisited Addressing Effort and Risk Concerns Dissertation submitted in fulfillment of the requirements for the degree of Doktoringenieur (Dr.-Ing.) by Sebastian Heil M.Sc. September 24, 2020 Dissertation Committee: Prof. Dr.-Ing. Martin Gaedke Prof. Dr. Maximilian Eibl Assoc.-Prof. Maxim Bakaev, PhD Sebastian Heil M.Sc. Web Migration Revisited: Addressing Effort and Risk Concerns Dissertation Committee: Prof. Dr.-Ing. Martin Gaedke (Technische Universität Chemnitz), Prof. Dr. Maximilian Eibl (Technische Universität Chemnitz) Assoc.-Prof. Maxim Bakaev, PhD (Novosibirsk State Technical University) Submitted on December 12, 2019 Defended on September 24, 2020 Technische Universität Chemnitz Faculty of Computer Science Distributed and Self-Organizing Systems Group Straße der Nationen 62 09111 Chemnitz Abstract Web Systems are widely used and accepted due to their advantages over traditional desktop applications. Modernization of existing non-Web software towards the Web, however, is a complex and challenging task due to the characteristics of Legacy Systems. Independent Software Ven- dors are struggling to commence Web Migration because of the involved effort and risk. Through systematic field research and problem analysis, this situation is further analyzed, deriving a set of requirements that rep- resent the effort and risk concerns and which are used to assess the state of the art in the field. Existing Web Migration research exhibits gaps concerning dedicated approaches for the initial phase and feasibility of the proposed strategies with limited resources and expertise. This thesis proposes a solution to address the shortcomings outlined above and to support Independent Software Vendors to commence Web Migration, focusing on their concerns about effort and risk. The main idea is to provide a set of dedicated solutions to close the identified gaps in the form of a methodology and a supporting toolsuite that transfer paradigms successfully solving similar problems in other areas of computer science into the Web Migration domain. These solutions constitute the proposed approach called Agile Web Migration for SMEs (AWSM), consisting of methods, tools, principles, and formalisms for reverse engineering, risk management, customer impact control, and migration strategy selection. vii The thesis describes the research on the devised ideas in the context of a collaboration project with an Independent Software Vendor. Ap- plicability and feasibility of the concepts are demonstrated in several evaluation experiments, integrating empirical user studies and objec- tive measurements. The thesis concludes with an evaluation based on requirements assessment and on the application of the solutions in the application scenario, and it provides an outlook towards future work. viii Acknowledgment I would like to express my gratitude to all who have accompanied me throughout the years of research as a PhD student, in particular to: My supervisor Prof. Dr.-Ing. Martin Gaedke for introducing me to the challenging but exciting world of research, for his inspiring vision and ideas, and for giving me the opportunity to learn and grow under his guidance in a supportive and motivating environment that he created and to collaborate with many international researchers. To all my colleagues and dear friends with whom I had the honor to collaborate on various research projects, who have widened my research interests and from whom I have learned so many things, I owe so much. Here, I would like to especially mention Maxim Bakaev, Mahda Noura, Stefan Wild, Alexey Tschudnowsky, Julian Grigera, José Matías Rivero, Bahareh Zarei, and Maximilian Speicher. I am very grateful to all students and colleagues who contributed to my research presented in this thesis: Felix Förster, Valentin Siegert, Tobias Lang, Thomas Weber, Frank Siegel, Anna Scholz, Philipp Oehme, Markus Keller, Stefan Staude, and Hao Li, and to Ralph Sontag, who has always encouraged me and spent countless hours helping me to typeset this thesis. I cordially thank my friend Mahsa Sodeiri for helping me design the book cover for the print version of this thesis. I thank all present and former colleagues at VSR – André Langer, Maik Benndorf, Michael Krug, Fabian Wiedemann, Jörg Anders, Markus Ast, Christoph Brandt, Dang Vu Nguyen Hai, Felix Kettner, and Verena ix Traubinger – for inspiring and fruitful discussions, continuous knowl- edge sharing, and a friendly and welcoming atmosphere that has lead me through the harder times in my PhD student life. Prof. Dr.-Ing. Martin Gaedke did an excellent job in putting the VSR team together. Thank you also to my three reviewers for their encouraging feedback and support to successfully write, defend, and publish this thesis, as well as to the members of the PhD commission, Prof. Dr.-Ing. Janet Siegmund, Dr. Andreas Müller, and Dr. Frank Seifert. Also, I like to thank all student assistants and students advised by me for enabling me to focus on my research and teaching me how to communicate ideas and organize research activities. Finally, I am very grateful to my mother for her ongoing encourage- ment, appreciation, understanding, love and care, and to Michalina Kunecka, Sven R. Kunze, Christian Jager, Bastian Weiß, Gabriela Bosetti, Radka Nacheva and many more of my friends whom I have not already mentioned above, who all supported me, raised me up and kept close contact in spite of the sometimes limited availability resulting from the PhD challenge. x Dissemination In order to substantiate this work and comply with high academic standards, parts of the research results this dissertation is based on have been disseminated before. All relevant publications are listed in the following: Heil, Sebastian, Maxim Bakaev, and Martin Gaedke (2016). “Measuring and Ensuring Similarity of User Interfaces: The Impact of Web Layout”. In: Web Information Systems Engineering – WISE 2016. Ed. by Wojciech Cellary, Mohamed F. Mokbel, Jianmin Wang, et al. Cham: Springer International Publishing, pp. 252–260. Heil, Sebastian, Felix Förster, and Martin Gaedke (2018). “Exploring Crowdsourced Reverse Engineering”. In: Proceedings of the 13th In- ternational Conference on Evaluation of Novel Approaches to Software Engineering - Volume 1: ENASE. Funchal, Portugal: SciTePress, pp. 147– 158. Heil, Sebastian and Martin Gaedke (2016). “AWSM – Agile Web Migra- tion for SMEs”. In: Proceedings of the 11th International Conference on Evaluation of Novel Approaches to Software Engineering - Volume 1: ENASE. Rome, Italy: SciTePress, pp. 189–194. – (2017). “Web Migration – A Survey Considering the SME Perspective”. In: Proceedings of the 12th International Conference on Evaluation of Novel Approaches to Software Engineering - Volume 1: ENASE. Porto, Portugal: SciTePress, pp. 255–262. Heil, Sebastian, Valentin Siegert, and Martin Gaedke (2018). “ReWaMP: Rapid Web Migration Prototyping Leveraging WebAssembly”. In: Web xi Engineering: Proceedings of 18th International Conference on Web En- gineering (ICWE2018). Ed. by Tommi Mikkonen, Ralf Klamma, and Juan Hernández. Caceres, Spain, pp. 84–92. Heil, Sebastian, Valentin Siegert, and Martin Gaedke (2019). “Crowd- sourced Reverse Engineering: Experiences in Applying Crowdsourc- ing to Concept Assignment”. In: Evaluation of Novel Approaches to Software Engineering, Revised Selected Papers, Communications in Computer and Information Science. Ed. by Ernesto Damiani, George Spanoudakis, and Leszek Maciaszek. Springer, pp. 215–239. Bakaev, Maxim, Sebastian Heil, Vladimir Khvorostov, and Martin Gaedke (2018). “HCI Vision for Automated Analysis and Mining of Web User Interfaces”. In: Web Engineering: Proceedings of the 18th International Conference on Web Engineering (ICWE2018). Ed. by Tommi Mikkonen, Ralf Klamma, and Juan Hernández, pp. 136–144. – (2019). “Auto-Extraction and Integration of Metrics for Web User Interfaces”. In: Journal of Web Engineering 17.6, pp. 561–590. Bakaev, Maxim, Sebastian Heil, Nikita Perminov, and Martin Gaedke (2019). “Integration Platform for Metric-Based Analysis of Web User Interfaces”. In: Web Engineering: Proceedings of 19th International Conference on Web Engineering (ICWE2019). Ed. by Maxim Bakaev, Flavius Frasincar, and In-Young Ko. Daejeon, Korea: