This TCLEE Monograph provides engineers and decision makers with tools to help them better understand acceptable risk processes and then develop risk reduction strategies and implement mitigation actions to reduce lifeline losses from future earthquakes. The disruption of lifelines from natural hazards has a direct impact on the world's regional economies and the health of their citizens. Therefore, it is important to understand what natural hazards are, how they can affect infrastructure lifelines, and what can be done to minimize their impact. These three elements, in turn, influence decisions that involve acceptable risk processes. The topic of "acceptable risk" provides one way of bringing integrated systems risk evaluations for disaster explicitly into a decision-making context. Topics include technical issues; risk criteria issues; and communication, administration, and regulation issues.