Quantitative Weight and Sum

Quantitative weight and sum (also called numerical weight and sum, or NWS) is a numerical synthesis methodology for summing evaluand performance across multiple criteria. NWS involves ascribing numerical values to criteria that represent importance, using a fixed-length numerical scale to score the evaluand on each criterion, multiplying weights by scores, and then summing these products. The resulting sum represents the overall merit of the evaluand. NWS works adequately for ranking provided that (a) there is a small number of criteria; (b) there is some other mechanism for taking into account “bars” (minimum levels of acceptable performance); and (c) there is a defensible, needs-based strategy for ascribing weights. For other ranking tasks, use qualitative weight and sum.