Highly optimized tolerance: Robustness and design in complex systems

Highly optimized tolerance (HOT) is a mechanism that relates evolving struc ture to power laws in interconnected systems. HOT systems arise where desig n and evolution create complex systems sharing common features, including ( 1) high efficiency, performance, and robustness to designed-for uncertainti es, (2) hypersensitivity to design flaws and unanticipated perturbations, ( 3) nongeneric, specialized, structured configurations, and (4) power laws. We study the impact of incorporating increasing levels of design and find t hat even small amounts of design lead to HOT states in percolation.