This book includes a set of selected papers from the first "International Conference on Enterprise Information Systems," (ICEIS'99) held in Seรtbal, Portugal, from 27 to 30 March 1999. ICEIS focuses on real world applications and aims at becoming a major point of contact between research scientists, engineers and practitioners in the area of business applications of information systems. This year four simultaneous tracks were held, covering different aspects related to enterprise computing, including: Systems Analysis and Specijication, Database Technology and its Applications, Artijicial Intelligence and Decision Support Systems, and Internet and Intranet Computing. Although ICEIS'99 received more than 200 submissions, only 96 papers were accepted for oral presentation and only 24 were selected for inclusion in this book. These numbers demonstrate stringent quality criteria and the intention of maintaining a high quality forum for future editions ofthis conference. A number of additional keynote lectures, case studies and technical tutorials were also held. These presentations, by specialists in different knowledge areas made an important contribution to increase the overall quality of the Conference, and are partially expressed in the first two papers of the book.