Proceedings of the ASME
Design Theory and Methodology Conference DTM '93
(September 1993), ASME, pages 167-173.
Abstract
Two methods have been proposed for manipulating uncertainty reflecting
designer choice: utility theory and the method of imprecision. Both
methods represent this uncertainty across decision making attributes
with zero to one ranks, higher preference modeled with a higher rank.
The two methods can differ, however, in the combination metrics used to
combine the ranks of the incommensurate design attributes. Utility
theory resolves the multi-attributes using various well proven additive
metrics. In contrast, the method of imprecision resolves by also
considering non-additive metrics, such as ranking by the worst case
performance or by multiplicative metrics. The axioms of utility theory
are appropriate for designs where it is deemed the attributes can always
be traded off, even to the point of achieving zero preference in some
attributes. In the case of a design with attributes which cannot have
zero preference, such as stress limits or maximum allowed cost, the
method of imprecision is more appropriate: it trades off attribute
levels without permitting any of them to be traded off to zero
performance.