A fuzzy decision aid model for environmental performance assessment in waste recycling

This study introduces a methodological framework for environmental performance assessment of waste recycling programs. We develop two categories of indicators: the efficiency indicators that compare the environmental achievements of a program with the required expenditures (benefits per unit cost), and the effectiveness indicators that compare the environmental benefits of a program with the amount of generated wastes (benefits per unit waste). Aggregation of these indicators, in relation with their associated criticalities, will give us a number of environmental performance indices to represent the status of the environmental performance. This score-based assessment has two major advantages: it takes complex scientific information and synthesizes it in a way that makes it easily understandable for non-experts while in comparison with other environmental performance assessment methods it is not computationally intensive. In this aggregation, the importance values (criticalities) are often expert based uncertain judgments, which are defined according to the objective of performance assessment. Therefore, a fuzzy multiple attribute analysis can be employed to express these judgments by fuzzy sets and to formulate the weighted aggregation process. For case study, we have investigated the environmental performance of the provincial beverage container recycling programs in Canada, which illustrates the applicability of the proposed methodology.