Aggregation Functions for Engineering Trade-off Calculations

Manuscript prepared for submission to the ASME 1995 Design Theory and Methodology Conference.

Michael J. Scott
Engineering Design Research Laboratory
California Institute of Technology
Pasadena, California 91125
mjscott@design.caltech.edu

Erik K. Antonsson
Engineering Design Research Laboratory
Division of Engineering and Applied Science
California Institute of Technology
Pasadena, California 91125

The Method of Imprecision (MoI) is a formal theory for the manipulation of preliminary design information that represents preferences among design alternatives with the mathematics of fuzzy sets. Using the MoI, different design trade-off strategies can be applied. To date, two aggregation functions have been developed for the MoI, one representing a compensating strategy and one a non-compensating strategy. Other research on aggregation functions on fuzzy sets has focused on two classes of functions that are not suitable for engineering design. The general restrictions on design-appropriate aggregation functions are discussed, and a family of functions ranging from the non-compensating to the compensating is presented. An application to preliminary engineering design is given.