A scenario can be defined as a description of a possible set of events that might reasonably take place. The purpose of scenarios is to stimulate thinking about possible occurrences, assumptions relating these occurrences, possible opportunities and risks, and courses of action. Recent surveys of scenario research and practice undertaken by the European CREWS project show the enormous variety, but also the fragmentation of the field. For example, HCI researchers use scenarios to enhance user-designer communications and managers use scenarios to explore alternative futures and the impact of systems. Software engineers see scenarios as a promising means to discover user needs that are not obvious in analysis situations, to better describe the use of system in work processes, and to systematically explore normal-case and exceptional behavior of a system and its environment.

Researchers from other disciplines have used scenario analysis for a long time. Economists have successfully used scenarios for long-range planning. Management scientists use scenarios for strategic decision-making. Policy makers use scenarios to weigh the possible consequences of their actions. In an interdisciplinary perspective, scenarios are used to examine the interplay among economic, social, and technological issues.

This Dagstuhl Seminar convened twenty-four leading researchers and practitioners from various disciplines to cross-examine the effectiveness and efficiency of using scenarios as a modeling, design, development, and implementation tool. A second issue of interest is the management of scenarios as complex artifacts throughout the planning and systems lifecycle.

The seminar was organized by the CREWS ESPRIT project in cooperation with the IFIP Working Group 2.9 (Requirements Engineering) and the RENOIR European Network of Excellence. It comprised plenary sessions as well as subgroup discussions, as shown on the Agenda on the next pages. This is followed by short abstracts of presentations written by participants. Afterwards, the results of the workshop discussions are summarized in an overview article by the organizers, titled "Scenario Management: An Interdisciplinary Approach4. 13 individual research contributions by the participants and others, elicited through an open Call for Papers, are published in Special Issues of the IEEE Transactions on Software Engineering (vol. 24, no. 12, December 1998) and of the Requirements Engineering Journal (vol. 3, no. 3-4, December 1998). The editorials and tables of contents of both issues conclude this report.

Thanks are due to the Dagstuhl Directorate for accepting this interdisciplinary event, and to the European Commission for supporting the travel of many participants via CREWS and RENOIR. Without the enthusiastic cooperation of all participants, reacting well to frequent agenda changes and spontaneous discussions, this workshop would not have been the success we feel it has been. Special thanks go to the conveners of the subgroups, and to our students Camille Ben Achour, Sebastian Brandt, George Chin, Peter Haumer, Patrick Heymans, Sheiley Minocha, for their support in organization and session recording. As always, the final thanks go to the cheerful people at Dagstuhl without whose support these events would be much more work and much less fun.