A cost estimate for a project such as the acquisition of a new aircraft or satellite system carries with it an inherent probability that the actual cost will exceed the estimate-that changes in requirements, technology, the economic environment, and a multitude of other factors that may occur over the life of the project will change the final cost. One major approach to cost risk analysis-the evaluating and quantifying of the uncertainty of a cost estimate-has been probabilistic: expressing the uncertainty in a cost estimate as a probability distribution over a range of potential costs. Cost analysts in industry and government and researchers in statistics and management have often proposed that, to get probability distributions for platforms using new and untried technologies, expert judgment should be tapped and subjective probability distributions elicited from the experts to represent cost uncertainty. This technical report reviews procedures for eliciting subjective probability distributions in cost risk analysis, both in the cost risk field and in other disciplines in which elicitation has been a topic of research-primarily, statistics and psychology. Because of a lack of empirical work in elicitation, especially in cost risk, the author also interviewed a number of senior people in the cost risk community, who gave insight into the practices of the field. This report should be of interest to cost analysis professionals who wish to quantify uncertainty when using expert opinions in cost risk analysis.

In April 1991 BusinessWeek ran a cover story entitled, "I Can't Work This ?#!!@ Thing," about the difficulties many people have with consumer products, such as cell phones and VCRs. More than 15 years later, the situation is much the same-but at a very different level of scale. The disconnect between people and technology has had society-wide consequences in the large-scale system accidents from major human error, such as those at Three Mile Island and in Chernobyl. To prevent both the individually annoying and nationally significant consequences, human capabilities and needs must be considered early and throughout system design and development. One challenge for such consideration has been providing the background and data needed for the seamless integration of humans into the design process from various perspectives: human factors engineering, manpower, personnel, training, safety and health, and, in the military, habitability and survivability. This collection of development activities has come to be called human-system integration (HSI). Human-System Integration in the System Development Process reviews in detail more than 20 categories of HSI methods to provide invaluable guidance and information for system designers and developers.