A grey hop, skip, and jump approach: generating alternatives for expansion planning of waste management facilities

A grey hop, skip, and jump (GHSJ) approach is developed and applied to the area of municipal solid waste management planning. The method improves upon existing modelling to generate alternative approaches by allowing uncertain information to be effectively communicated into the optimization process and resulting solutions. Feasible decision alternatives can be generated through interpretation of the GHSJ solutions, which are capable of reflecting potential system condition variations caused by the existence of input uncertainties. Results from a hypothetical case study indicate that useful solutions for the expansion planning of waste management facilities can be generated. The decision alternatives obtained from the GHSJ solutions may be interpreted and analyzed to internalize environmental–economic tradeoffs, which may be of interest to solid waste decision makers faced with difficult and controversial choices. Key words: grey programming, modelling to generate alternatives, hop-skip-jump approach, waste management planning, uncertainty, public sector decision making.