End-User Driven Business Process Composition vom Fachbereich Informatik der Technischen Universität Darmstadt genehmigte Dissertation zur Erlangung des akademischen Grades eines Doktor-Ingenieurs (Dr.-Ing.) von Diplom-Ingenieur Todor Stoitsev aus Sofia, Bulgarien Referent: Prof. Dr. Max Mühlhäuser Korreferent: Dr. Fabio Paternò Tag der Einreichung: 05 Mai 2009 Tag der Mündlichen Prüfung: 17 Juni 2009 Darmstadt 2009 Hochschulkennziffer D17 Ehrenwörtliche Erklärung Hiermit erkläre ich, die vorgelegte Arbeit zur Erlangung des akademischen Grades “Dr.-Ing.” mit dem Titel “End-User Driven Business Process Composition” selbständig und ausschließlich unter Verwendung der angegebenen Hilfsmittel erstellt zu haben. Ich habe bisher noch keinen Promotionsversuch unternommen. Darmstadt, den 30.04.2009 Dipl.-Ing. Todor Stoitsev Acknowledgments Writing a dissertation is an ambitious endeavor which is hardly possible without support from various directions. This dissertation is not an exception. Therefore I would like to thank all people who supported me on my way to the doctoral degree. My thanks go to: x My advisor Prof. Dr. Max Mühlhäuser for providing me with valuable guidance and teaching me to look beyond the horizon. This dissertation would not have been possible without him. x My co-supervisor Dr. Fabio Paternò for the kind support and constructive feedback on the concepts developed in the thesis. x Dr. Knut Manske who believed in me and encouraged all my achievements on the path to the dissertation. x Dr. Stefan Scheidl for his extraordinary engagement in helping me to settle down in Germany, for preparing a fruitful ground for the research in the thesis and for assisting me in the different phases of my research. x Dr. Felix Flentge for the constructive feedback on concepts developed in the thesis. x Dr. Nicolay Mehanjiev for the fruitful cooperation on the empirical questionnaire studies and for providing guidance on end-user development topics. x Dr. Uwe Riss and Olaf Grebner for the cooperation on the task management and task pattern concepts. x Michael Spahn for the teamwork and for being with me in the trenches. x Dr. Birgit Zimmermann for the constructive feedback on the research concepts and for taking care of the research project and leaving me space to work on the dissertation. x Victoria Carlsson for her vital support in the preliminary empirical studies and task analysis. x Daniel Zwicker, Teena Vellaramkalayil, Axel Schulz, Simon Stebbins, and Markus Wiemann for their contributions to the development of the CTM system. x All colleagues from the Telecooperation Group at the Darmstadt University of Technology and at SAP Research CEC Darmstadt for the friendly working atmosphere and the valuable feedback on my research in the doctoral seminars. x All people from the industrial partner companies who participated in the user studies and evaluation phases. x Above all, I would like to thank to my beloved wife Brigita Zareva-Stoitseva, for her love and care, for helping me not to forget the really important things in life and for making it all worthwhile. Darmstadt, April 2009 Abstract Business Process Management (BPM) solutions enable enterprises to consolidate and optimize their business operations and to gain competitive advantage in the fast evolving global market. Often, the only ones to understand the matter and complexity of business processes are the end users of enterprise software, who execute them on a daily basis. The need to involve end users in business process composition during the implementation of BPM solutions in enterprises is clearly perceived. However, end users have a detailed domain expertise but limited technical skills. Therefore upfront process modeling through conventional modeling notations remains inaccessible for them. The need for user-centric process composition approaches arises, which can enable end users to tailor business processes according to their actual expertise and problem solving strategies. Furthermore, these approaches need to bridge the process understanding of end users and technically skilled process designers and developers in the course of workflow projects in order to facilitate the development of real-life compliant and consistent process models and to streamline the uptake of BPM software in enterprises. This thesis addresses end-user driven composition of both: (i) weakly-structured process models for supporting underspecified, human-centric business processes and (ii) structured business process models for automation of rigidly recurring processes through workflow engines. Both process types are composed through programming by example in a collaborative task management system. Task management is chosen as a starting point for end-user driven process composition in order to reconcile the personal and the enterprise perspectives on business processes. Programming by example is an end-user development technique, which enables capturing and repeated execution of user activities in a software system. The application of this technique in an enterprise scope for the composition of business process models is novel and requires specific support from user’s perspective and from formal system’s perspective. The four major scientific contributions of the thesis can be captured as: (i) a task management model for human-centric business processes; (ii) a method for composition of weakly-structured process models through collaborative task management; (iii) a method for transformation of weakly-structured process models to structured workflows and their refinement based on deviations with ad-hoc tasks at runtime; (iv) the holistic concept for end-user driven business process composition through programming by example, composing contributions (i) through (iii) into a seamless overarching method and architecture for the composition of weakly-structured and structured process models. The elaborated concepts provide a significant contribution to known process modeling approaches in various research areas such as human-computer interaction, BPM, workflow management and computer supported cooperative work. The presented concepts found on preliminary empirical studies, comprising an online questionnaire distributed to a number of companies from various industries, and a series of field studies in three German small and medium enterprises. The preliminary studies deliver strong support for end-user development in the domain of task management and identify entry points for introducing process tailoring to end users. These studies provide input for the elaborated task management model and drive the design choices for the architecture, underling the presented holistic concept. The presented concepts take into consideration existing end user work practices and software applications for management of day-to-day activities, such as email and personal to-do list applications delivered with standard office environments. The task management model enables aggregation of data from these applications for the composition of weakly-structured business process models. These models can be repeatedly adapted and reused for the execution of ad-hoc, human-centric processes. The method for generation of structured workflows from weakly- structured process models enables automation of rigidly recurring processes through workflow engines. Generated workflows can be extended by process designers and developers, in a shared context between user-defined and formal process models. The mapping of weakly-structured process models to structured workflow models facilitates data reuse between ad-hoc and operational processes. Enhanced data sharing and interoperability between ad-hoc and structured processes is enabled through the introduced holistic concept and the underlying architecture. The presented concepts have been implemented and validated through a prototype called Collaborative Task Manager. The evaluation results confirm that the proposed end-user development approach and its enterprise-wide application through the presented concepts efficiently enable end-user driven business process composition. Thus the specified task management model, methods and holistic concept can be used for designing user-tailorable BPM systems that facilitate the adoption of BPM technology in enterprises. Keywords: end-user development, human-computer interaction, business process management, workflow modeling, computer-supported cooperative work, knowledge management. Zusammenfassung Geschäftsprozessmanagementlösungen ermöglichen es Unternehmen ihre Geschäftsabläufe zu konsolidieren und zu optimieren, und dadurch einen Wettbewerbsvorteil in der sich schnell entwickelnden Marktumgebung zu erzielen. Sehr oft sind die einzigen Personen, die Geschäftsprozesse im Detail kennen, die Endanwender von Unternehmenssoftware, die diese Geschäftsprozesse im Rahmen ihrer täglichen Arbeitspraxis ausführen. Hierdurch entsteht die Notwendigkeit, Endanwender in die Komposition von Geschäftsprozessen während der Implementierung von Geschäftsprozessmanagementlösungen in Unternehmen einzubeziehen. Endanwender besitzen eine detaillierte Fachexpertise, aber nur begrenzte technische Fähigkeiten. Eine explizite Prozessmodellierung durch konventionelle Modellierungssprachen und -umgebungen ist den Endanwendern selbst daher nicht unmittelbar möglich. Anwenderzentrische Ansätze zur Geschäftsprozesskomposition werden benötigt, die Endanwender in der Lage versetzen, Geschäftsprozesse entsprechend der eigenen Fachexpertise und Problemlösungsstrategien zu modellieren