ABSTRACT

This chapter explores complexity science and complex network theory (CNT). It resists the urge to plummet immediately into ATM examples. Complexity science is the multidisciplinary study of complex systems. Many of the roots of complexity science can be traced back to statistical physics, non-linear dynamics and information theory, Anderson, 1972, although a consensual definition of complexity science still does not exist. Generic topological properties are present in different complex systems, suggesting that some general principles govern the creation, growth and evolution of such networks. Indeed, as may be expected, the initial analyses of the topology of the Internet paved the way to the study of its vulnerability to random failure or attacks. The chapter has introduced the main facets of CNT: how networks arise in natural and man-made systems, how they can be characterised, and insights into how an understanding of network structure could be used to improve operational performance and resilience.