Risk Measures in Engineering Design under Uncertainty

Engineering decisions are invariably made under substantial uncertainty about current and future system cost and response, including cost and response associated with low-probability, high-consequence events. A risk-neutral decision maker would rely on expected values when comparing designs, while a riskaverse decision maker might adopt nonlinear utility functions or failure probability criteria. The paper shows that these models for making decisions fall within a framework of risk measures that includes many other possibilities. General recommendations for selecting risk measures lead to decision models for risk-averse decision making that comprehensively represent risks in engineering systems, avoid paradoxes, and accrue substantial benefits in subsequent risk, reliability, and cost optimization. The paper provides an overview of the framework of decision making based on risk measures and illustrates the approach in a truss design example.