Modern software systems typically consist of massive numbers of components, featuring complex interactions among components and with humans and other systems. Each component in the system may exhibit autonomic behaviour depending on its properties, objectives and actions. Decision-making in such systems is complicated and interaction between the components may introduce new and sometimes unexpected behaviours. This class of systems is usually referred to as Collective adaptive systems (CAS). CAS present a significant research challenge in terms of both representation and reasoning about their behaviour. The pervasive yet transparent nature of the applications developed in this paradigm makes it of paramount importance that their behaviour can be thoroughly assessed during their design, prior to deployment, and throughout their lifetime. Indeed their adaptive nature makes modelling essential and models play a central role in driving their adaptation. Moreover, the analysis should encompass both functional and non-functional aspects of behaviour. Thus it is vital that we have available robust modelling techniques which are able to describe such systems and to reason about their behaviour in both qualitative and quantitative terms. To move towards this goal, it is important to develop a theoretical foundation for CAS that will help in understanding their distinctive features. From the point of view of the language designers, the challenge is to devise appropriate abstractions and linguistic primitives to deal with the large dimension of systems, to guarantee adaptation to (possibly unpredicted) changes of the working environment, to take into account evolving requirements, and to control the emergent behaviours resulting from complex interactions. Attributed based communication has been recently introduced as a new interaction paradigm to model typical interactions in CAS: involved agents are equipped with a set of attributes while the participants of an interaction are identified by predicates over attributes.
In this talk we will first introduce attribute based communication; then we will show how it impacts on the general process of CAS design. We will also show how this paradigm has been integrated in process specification languages and how these can be used to support specification, modelling, analysis and monitoring of CAS.