Preface The iStar workshop series is dedicated to the discussion of concepts, methods, techniques, tools, and applications associated with i* and related approaches. Following successful workshops in Trento, Italy (2001), London, England (2005), Recife, Brazil (2008), Hammamet, Tunisia (2010), Trento, Italy (2011), Valen- cia, Spain (2013), Thessaloniki, Greece (2014), Ottawa, Canada (2015), Beijing, China (2016), and Essen, Germany (2017), this year, the 11th International i* Workshop (iStar’18) was held in Tallinn, Estonia. As with previous editions, the objective of the workshop was to provide a unique opportunity for researchers in the area to exchange ideas, compare notes, and forge new collaborations. This year, the workshop was in conjunction with the 30th International Conference on Advanced Information Systems Engineering (CAiSE’18), benefiting from our common themes and interests shared by the two events. We kept the workshop format informal so as to promote and maximize inter- action. Aiming at an inclusive and discussion-oriented workshop, the main crite- rion for paper acceptance in iStar’18 was relevance and potential for stimulating discussion and possible collaborations among the participants. A 33-member program committee, consisting of scholars and practitioners with expertise and interest in the field, were involved in reviewing a total of 10 complete paper sub- missions. Each of the papers was reviewed by three program committee members. Of the submitted papers, 8 were accepted for presentation in the workshop and revised versions of the papers are included in the proceedings that follow. In the event, each paper was given 30 minutes for presentation and discussion. iStar’18 included a keynote by Prof. Oscar Pastor, from Universitat Politècnica de València, entitled Making Software Fulfill Users Goals: From Goals to Code. Finally, iStar’18 also included a 1h30 panel with the participation of Giancarlo Guizzardi, Oscar Pastor and Jolita Ralyte, on iStar modelling in practice: strengthening interdisciplinary research. We would like to thank all the members of the Program Committee and the additional reviewers for providing their expertise and suggesting constructive advises to improve the quality of the submissions. Last but not least, we want to thank the organizers of the CAiSE 2018 conference for their valuable support. Tallinn, June 12, 2018 Miguel Goulão, Marcela Ruiz and Angelo Susi Program Co-Chairs iStar’18 II Program Committee Raian Ali Bournemouth University, UK Daniel Amyot University of Ottawa, Canada João Araújo Universidade Nova de Lisboa, Portugal Basak Aydemir Utrecht University, The Netherlands Amel Bennaceur The Open University, UK Juan Pablo Carvallo Universidad del Azuay, Ecuador Jaelson Castro Universidade Federal de Pernambuco, Brazil Dolors Costal Universitat Politècnica de Catalunya, Spain Luiz Marcio Cysneiros York University, UK Fabiano Dalpiaz Utrecht University, The Netherlands Neil Ernst Software Engineering Institute, USA Hugo Estrada CENIDET, Mexico Sepideh Ghanavati Texas Tech University, USA Renata Guizzardi Universidade Federal do Espirito Santo, Brazil Jennifer Horkoff Chalmers UT and University of Gothenburg, Sweden Tong Li Beijing University of Technology, China Sotirios Liaskos York University, UK Lin Liu Tsinghua University, China James Lockerbie City University London, UK Lidia Lopez Universitat Politècnica de Catalunya, Spain Alejandro Maté University of Alicante, Spain Haralambos Mouratidis University of East London, UK Elda Paja University of Trento, Italy Oscar Pastor Universitat Politècnica de Valencia, Spain Michalis Pavlidis University of Brighton, UK Anna Perini Fondazione Bruno Kessler, Italy Alberto Siena Delta Informatica, Italy Vitor E. Silva Souza Universidade Federal do Espirito Santo, Brazil Yvesv Wautelet Katholieke Universiteit Leuven, Belgium Eric Yu University of Toronto, Canada Yijun Yu The Open University, UK Jelena Zdravkovic Stockholm University, Sweden Marc van Zee University of Luxembourg, Luxembourg Additional Reviewers Jameleddine Hassine King Fahd University of Petroleum and Minerals, Saudi Arabia Steering Committee Xavier Franch Universitat Politècnica de Catalunya, Spain John Mylopoulos University of Trento, Italy Eric Yu University of Toronto, Canada III Program Co-Chairs Miguel Goulão Universidade Nova de Lisboa, Portugal Marcela Ruiz Utrecht University, The Netherlands Angelo Susi Fondazione Bruno Kessler, Italy