Risk, Uncertainty, and Reliability of Engineering Systems

What Is Risk Assessment and Management?

Risk and uncertainty are fundamental elements of modern life. They are ever present in the actions of human beings and they are frequently magnified in large-scale technological systems. Risk and uncertainty must be managed effectively to protect people from injury and to permit the development of reliable, high-quality products. Nations that successfully address the risk and uncertainty caused by future product designs, resource availability, natural forces, market changes, and the reliability of man/machine/software systems will dominate the technological world. Today an ever-increasing number of professionals and managers in industry, government, and academia are devoting a larger portion of their time and resources to the task of improving their approach to, and understanding of, risk-based decision-making. Indeed, decision-making under uncertainty literally encompasses every facet, dimension, and aspect of our lives.

Risk is often defined as a measure of the probability and severity of adverse effects. Risk management is commonly distinguished from risk assessment, even though some may use the term risk management to connote the entire process of risk assessment and management. In risk assessment, the analyst often attempts to answer the following set of triplet questions: What can go wrong? What is the likelihood that it would go wrong? And, what are the consequences? Answers to these questions help risk analysts identify, measure, quantify, and evaluate risks and their consequences and impacts. Risk management builds on the risk assessment process by seeking answers to a second set of three questions: What can be done? What options are available and what are their associated trade-offs in terms of all costs, benefits, and risks? And what are the impacts of current management decisions on future options?

To be effective and meaningful, risk management must be an integral part of the overall management of a system. This is particularly important in the management of technological systems, where the failure of the system can be caused by the failure of the hardware, the software, the organization, or the humans. Furthermore, the education of engineers and scientists often lacks a consideration of risk management and its impact on industrial competitiveness and public safety. We believe that the development of a systemic approach and the integration of risk-related topics into engineering education are highly important to our School and to the Nation.

Mission of the Center and the University of Virginia

UVa's internationally-recognized competence in "risk, uncertainty, and reliability" in engineering systems are central to the mission of our School of Engineering and Applied Science (SEAS) in two respects: (1) The assessment and management of risk, uncertainty, and reliability are critical to the success of any engineering venture today, including the strategic thrusts of SEAS. (2) In its own right, "risk, uncertainty, and reliability" is a significant, existing thrust of engineering research and education at UVa. Our development of theory and methodology at UVa in "risk, uncertainty, and reliability," and its transfer to engineering training and practice, is worthy and capable of continuing to increase the visibility and external support for the University's and SEAS's mission.

The mission of our Center for Risk Management of Engineering Systems is to develop technology to assist in the management of risk for a variety of engineering systems. Industry and government sponsors of research at the Center work closely with faculty and students, contributing their unique strengths and interests to the Center and sharing in experience from a broad range of projects ongoing at the Center. Our areas of expertise include: (1) environmental impacts, (2) water resources and technology management, (3) electronic, safety-critical systems, (4) computer-based systems, including hardware and software performance and reliability, and (5) reliability modeling of multiple failure modes in complex systems. Our Center is unique in many ways, including:

Applications of our work include: Environmental impact, hazardous waste, groundwater; water resources, inland navigation, water distribution; civil infrastructure; software acquisition; ground transportation, trains, subways; aircraft and space systems; and highway vehicle safety. Our sponsors include: Advanced Research Projects Agency, Alton Jones Foundation, Federal Bureau of Investigation, General Motors, Honeywell Technology Center, MITRE Corporation, NASA, NASA Langley Research Center, National Science Foundation, Naval Research Laboratory, Software Engineering Institute, Sol Telecommunications Services, Inc., TRW Corporation, Union Switch and Signal, US Army Harry Diamond Laboratory, US Army Corps of Engineers, US Environmental Protection Agency, Virginia Department of Waste Management, Virginia Environmental Endowment, and the Virginia Telephone Association.

Theory and methodology that are developed at the Center include reliability and risk decision making, multiple objectives, risk ranking, systems engineering and holographic modeling, systems integration, management decisions, CAD tools for reliability analysis, experimental evaluation of reliability and safety, simulation models and analysis, and economic analysis and resource allocation.

In 1995, the Center launched its Affiliate Program for technology managers in industry, government, and consulting organizations. The Affiliate Program brings together over thirty faculty from SEAS, the Darden School, the College of Arts and Sciences , and the School of Continuing Education for joint activities with the Affiliates that include: Interactions with graduate students and faculty; meeting for two-day workshops twice per year; consulting informally with faculty on technical and other issues; attending tutorials and workshops; engaging in dialogue with competitors in a cooperative environment; visitation of staff and professionals at the University of Virginia; sharing technical reports, articles, publications; accessing software tools; and advancing the state of knowledge and the cutting edge of research for risk management.

Yacov Y. Haimes
Barry W. Johnson
James H. Lambert


Mail comments to risk@virginia.edu.
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