This book contains the best papers of the 9th International Conference on Enterprise Information Systems (ICEIS 2007), held in the city of Funchal, Madeira (Portugal), organized by the Institute for Systems and Technologies of Information, Control and Communication (INSTICC) and the University of Madeira, in collaboration with ACM/SIGMIS and AAAI. Furthermore, the conference was sponsored by the Por- guese Foundation for Science and Technology (FCT). ICEIS has become a major point of contact between research scientists, engineers and practitioners in the area of business applications of information systems. This year, five simultaneous tracks were held, covering different aspects related to ent- prise computing, including: “Databases and Information Systems Integration,” “Arti- cial Intelligence and Decision Support Systems,” “Information Systems Analysis and Specification,” “Software Agents and Internet Computing” and “Human–Computer Interaction”. All tracks focused on real-world applications and highlighted benefits of information systems and technology for industry and services, thus making a bridge between academia and enterprise. Following the success of 2006, ICEIS 2007 received 644 paper submissions from more than 40 countries. In all, 72 papers were published and presented as full papers, i.e., completed work (8 pages in proceedings / 30-min oral presentations), 198 papers, reflecting work-in-progress or position papers, were accepted for short presentation and another 131 for poster presentation.