2000_Roser_DISSERTATION A Flexible Design Methodology

2000_Roser_DISSERTATION A Flexible Design Methodology

The flexible design methodology facilitates development of a minimal cost design that can later be adjusted for possible prediction uncertainties. Uncertainty arises in product development from assumptions and simplifications in the performance model, lack of certainty regarding the requirements, or simply errors in design development. Depending on the scope and impact of uncertainty, the design might have to be changed later in the product development cycle with negative impact on cost, performance, and development time. For a given design, the flexible design methodology determines all possible expected outcomes and their likelihood of occurrence. For each expected outcome, the likelihood and cost of all possible design changes are evaluated. An expected cost is then derived from analysis of the change costs and their joint probabilities of the expected outcomes and design changes. The expected cost, together with the failure probability, can assist the designer in developing a flexible design. The described methodology not only facilitates the trade-off between minimal cost and risk, but also evaluates the potential benefit of prediction models with improved prediction accuracies. The results indicate that a flexible design allows quick adjustment for uncertainties, with only a slight increase in the marginal part cost. Copyright Christoph Roser 2000