During the last few years, the functionality and complexity of software and systems in enterprise and non-commercial IT environments have increased a great deal. The result is soaring system management costs and increased likelihood of failures. There is a common understanding across researchers and engineers alike that enhancing systems with self-management capabilities is a promising way to tackle these challenges. These self-managing capabilities - frequently summarized under the term autonomic computing - include self-configuration, self-healing, self-optimization and self-protection. Recent years have brought a notable increase in related research activities, the driving forces being major IT players including IBM, HP, SUN, and Microsoft.

The Dagstuhl seminar "Self-Healing and Self-Adaptive Systems" focused on self-healing IT systems in the broader context of self-adaptive systems. Selfhealing refers to the automatic detection of failures and anomalies and their subsequent correction in a temporary or a permanent manner. Self-healing systems are of particular interest as they directly impact improvements in dependability. Self-adaptive systems are ones that monitor their execution environment and react to changes by modifying their behavior in order to maintain an appropriate quality of service. Obviously, there is a substantial intersection between self-healing and self-adaptiveness: self-healing systems may be viewed as a special kind of self-adaptive systems.

The overall goals of the seminar were

• to bring together experts from various disciplines and organisations for exchanging different viewpoints on the state of the art of methods and technologies for designing, implementing and evaluating of self-healing and selfadaptive systems,
• to foster open discussions on selected topics of the design space of such systems, and
• to facilitate community building in this increasingly important subject area.

In the invitations to the seminar participants three research fields were suggested in order to provide some structure for the presentations and discussions: fault detection and diagnosis, recovery and repair techniques, and frameworks and architectures for self-adapting systems. In order to establish a link between industrial practice and academic research, two focused application-oriented topics were intended to complement the seminar.

The Self-Healing and Self-Adaptive Systems seminar was a fertile meeting in which a diverse population of researchers have met. It included industry and academia, senior and junior researchers, multinational representation, and people coming from several disciplines. This diversity resulted in interesting and useful discussions, new understandings of the fundamental concepts and problems in the field, and in new collaborations on an array of problems which were not well defined or identified prior to this seminar.

Several work groups during the seminar not only generated new insights into specific topics in the field of self-healing and self-adaptive systems, but also initiated ongoing joint work, with group members continuing the work they started at the seminar.

The seminar included multiple presentations and discussions. Technical issues included all elements of the self-healing cycle, including monitoring, detection and diagnosis; recovery and repair techniques; testing, quality trust issue; and, architectures, infrastructure and use cases. The participants identified the need for better terminology and taxonomy for the field. They further indicated the need for case studies and benchmarks. Several participants stressed the need for trustworthy solutions. It was widely agreed that the potential of self-healing and self-adaptive systems is high, even though much of the existing work in this field is rather academic in nature, and industrial take-up has been relatively slow, with a few notable exceptions.

This seminar clearly illustrated the diversity, relevance, and fertility of the topics we presented and discussed. The intensity of the participants' involvement leads us to believe that the interactions fostered by the seminar will generate a lot of follow-up research, and eventually lead to practical use as well.