Decision Making on Engineering materials Based on Relative Grey Relation Analysis

The quality and cost of a product rely heavily on selecting suitable engineering materials, and therefore the ability to select the most appropriate material for a given application is the fundamental challenges faced by the design engineer. The general grey relational analysis (GRA) has three weaknesses: (1) weight determination depends only on expert judgments; (2) the qualitative indexes are only simply quantified with exact number; and (3) the general GRA only takes into account the relationship between the imaginarily best material and the candidate materials. The GRA is extended to RGRA, weights are determined by combining subjective and objective weights based on maximum deviation, and the qualitative indexes are fuzzily quantified through trapezoidal fuzzy number (TFN). The illustrative example shows that the presented method enables decision making results to be more reasonable and trustworthy.