Effectiveness Analysis of Automotive Systems

A methodology for assessing the effectiveness of an automotive system is developed. The analysis is carried out by characterizing separately both the system and the user´s needs in terms of quantitative attributes of performance. These attributes are determined as functions of primitives (independent design variables) that describe the automotive system, the user´s requirements, and their context. System capabilities and requirements are compared in a common attribute space by means of a geometric locus, on which certain partial measures of effectiveness can be computed. These partial measures are then combined to yield an overall effectiveness measure for studying design tradeoffs. The methodology is illustrated by assessing the effectiveness of a diesel powered passenger car with respect to fuel economy and emissions in the context of a simplified E.P.A. drive cycle. A key feature of the methodology is its ability to integrate complex data bases derived from simulation, laboratory test and analytical models as often found in automotive design.