This book describes new methods and techniques for the computer modelling of large-scale natural and man-made systems, characterised by a large dimension, high complexity, nonlinearity and uncertainty. The author emphasises the interdependence of complex system analysis, hybrid modelling and simulation, and knowledge-based and fuzzy control engineering. The theory relating to high complexity systems and hybrid mathemetical-heuristic modelling is presented in the first part of the text. Examples of applications in industrial systems, power systems, macroeconomic systems, aquatic ecosystems, terrestrial ecosystems and industrial chemical pollutants then follow. Providing a valuable new contribution to the field, the book will be of interest to a wide readerskip including lecturers, postgraduate students, system analysts, computer scientists, control engineers, and scientists and managers working in ecology, hydrology, forestry, air pollution, environmental protection, industry, power systems and macroeconomics.