Using multi-criteria decision-making to optimise solid waste management

Multi-Criteria Decision-Making (MCDM) encompasses a broad range of methods to support decision-making to reach a compromise solution when there are multiple criteria. One example of a multi-criteria problem is identifying the most sustainable solution to manage solid waste. In this case, different conflicting objectives exist, which can be categorised based on environmental, economic, social and technical metrics. In this article, the most relevant MCDM methodologies and tools are described and discussed, focusing on their applicability to assess solid waste management systems. The most relevant methodologies identified are the Analytic Hierarchy Process (AHP), Multi-Attribute Utility Theory (MAUT), Outranking procedures and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). A common weakness of these methodologies is that the evaluation criteria set by decision makers are generally subjective. It is recommended to integrate various methods and tools or to develop bespoke methodologies to optimise solid waste management.