%0 Book Section %A Bucchiarone, Antonio %A Mezzina, Claudio Antares %A Pistore, Marco %A Raik, Heorhi %A Valetto, Giuseppe %B Proceedings of Eighth International Conference on the Self-Adaptive and Self-Organizing Systems (SASO) %D 2014 %F eprints:2498 %I IEEE %K Collective adaptive systems; composition; dynamic adaptation; process; self-adaptation %P 151-156 %T Collective adaptation in process-based systems %U http://eprints.imtlucca.it/2498/ %X A collective adaptive system is composed of a set of heterogeneous, autonomous and self-adaptive entities that come into a collaboration with one another in order to improve the effectiveness with which they can accomplish their individual goals. In this paper, we offer a characterization of ensembles, as the main concept around which systems that exhibit collective adaptability can be built. Our conceptualization of ensembles enables to define a collective adaptive system as an emergent aggregation of autonomous and self-adaptive process-based elements. To elucidate our approach to ensembles and collective adaptation, we draw an example from a scenario in the urban mobility domain, we describe an architecture that enables that approach, and we show how our approach can address the problems posed by the motivating scenario. %Z SASO 2014 - Eighth IEEE International Conference on Self-Adaptive and Self-Organizing Systems, held in London (UK), 8-12 September 2014