Emergence in cyber-physical systems: potential and risk

Cyber-physical systems (CPSs) are distributed assemblages of computing, communicating, and physical components that sense their environment, algorithmically assess the incoming information, and affect their physical environment. Thus, they share a common structure with other complex adaptive systems, and therefore share both the possible benefits and the probable harmful effects of emergent phenomena. Emergence is an often unexpected pattern that arises from the interactions among the individual system components and the environment. In this paper we focus on three major problems concerning emergence in the context of CPSs: how to successfully exploit emergence, how to avoid its detrimental effects in a single CPS, and how to avoid harmful emergence that arises due to unexpected interaction among several independently developed CPSs that are operating in the same environment. We review the state of the research with regard to these problems and outline several approaches that could be used to address them.