December 14 – 19 , 2014, Dagstuhl Seminar 14512

Collective Adaptive Systems: Qualitative and Quantitative Modelling and Analysis


Jane Hillston (University of Edinburgh, GB)
Jeremy Pitt (Imperial College London, GB)
Martin Wirsing (LMU München, DE)
Franco Zambonelli (University of Modena, IT)


Matthias Hoelzel (LMU München, DE)

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Dagstuhl Report, Volume 4, Issue 12 Dagstuhl Report
Aims & Scope
List of Participants
Dagstuhl Seminar Schedule [pdf]


Modern systems are often structured as complex, multi-layered networks of interconnected parts, where different layers interact and influence each other in intricate and sometimes unforeseen ways. It is infeasible for human operators to constantly monitor these interactions and to adjust the system to cope with unexpected circumstances; instead systems have to adapt autonomously to dynamically changing situations while still respecting their design constraints and requirements. Because of the distributed and decentralized nature of modern systems, this usually has to be achieved by collective adaptation of the nodes comprising the system. In open systems exhibiting collective adaptation, unforeseen events and properties can arise, e.g. as side effects of the interaction of the components or the environment. Modelling and engineering collective adaptive systems (CAS) has to take into account such "emergent" properties in addition to satisfying functional and quantitative requirements.

Finding ways to understand and design CAS, and to predict their behaviour, is a difficult but important endeavour. One goal of this seminar was to investigate techniques for modelling and analysing systems that adapt collectively to dynamically changing environment conditions and requirements. In many cases, these models and analysis techniques should not only capture qualitative properties of the system, such as absence of deadlocks, they should also be able to express quantitative properties such as quality of service.

Research on CAS builds on and integrates previous research efforts from several areas:

  • Formal foundations and modelling techniques for concurrent systems deal with problems such as enabling and limiting concurrency, access to shared resources, avoidance of anomalies, communication between processes, and estimation of performance.
  • Analysis of concurrent systems typically exploits such notions as bisimilarity of different processes or reasons on stochastic properties of systems consisting of many equivalent processes.
  • The area of adaptive systems also investigates systems consisting of interacting entities, but is more concerned with the reaction of whole systems or individual actors in a system to a changing environment.

An important aim of this seminar was to combine research from concurrent systems with results from the adaptive systems community in order to develop formalisms for specifying CAS, to increase the scalability of qualitative and quantitative modelling and analysis techniques to large systems, and to apply them to systems that dynamically change their structure or adapt to novel situations.

The seminar was organised with a mixture of talks and working group sessions which facilitated more in-depth discussions and exploration of topics. In this report we include the abstracts of a selection of the presented talks, and three longer contributions compiled after the meeting which seek to reflect the activities of the working groups. The first group, considering modelling, specification and programming for CAS, start their presentation with brief descriptions of four diverse applications developed on the basis of CAS, ranging from national level power management to personal wearable devices. To complement this identification of application domains, the group also catalogued common and contrasting features that can be found in CAS@. This consideration highlights the role of physical space in all the considered domains and the urgent need to develop modelling and analysis techniques which reflect this central role played by space. This was key amongst a number of challenges identified by the group in their conclusions. Spatio-temporal aspects were also identified as a key challenge by the second working group who considered verification of CAS. The report from this group outlines the role of verification within the design and management of CAS ranging from seeking to guarantee global emergent behaviour from local specifications to using online verification to drive adaptation. Two specific challenges were explored in more detail, namely handling the inherent uncertainty in CAS, and specification and verification of spatial properties of systems composed of self-organising patterns. The third working group focused on the issues that arise from the recognition that some of the entities within a CAS may be humans and outside technological control, i.e. the design of socio-technical systems. A number of different scenarios are provided to illustrate the difference between socio-technical CAS and 'technical’ CAS, and the human factors which must be taken into account. To remediate some of the problems identified, the group propose the idea of a general intervention framework, based around the 3I life-cycle - inspection-innovation-intervention. It was foreseen that intervention would be achieved by shaping mechanisms, and the report goes on to describe some possible shaping mechanisms which were considered. To conclude a number of research challenges are discussed.

Summary text license
  Creative Commons BY 3.0 Unported license
  Jane Hillston and Jeremy Pitt and Martin Wirsing and Franco Zambonelli


  • Modelling / Simulation
  • Semantics / Formal Methods


  • Qualitative and quantitative reasoning
  • Autonomic and adaptive systems
  • Swarm computing
  • Self-awareness
  • Formal methods


In the series Dagstuhl Reports each Dagstuhl Seminar and Dagstuhl Perspectives Workshop is documented. The seminar organizers, in cooperation with the collector, prepare a report that includes contributions from the participants' talks together with a summary of the seminar.


Download overview leaflet (PDF).

Dagstuhl's Impact

Please inform us when a publication was published as a result from your seminar. These publications are listed in the category Dagstuhl's Impact and are presented on a special shelf on the ground floor of the library.


Furthermore, a comprehensive peer-reviewed collection of research papers can be published in the series Dagstuhl Follow-Ups.