Best–Worst Method and Simple Additive Weighting for Selection Problems in Process Systems Engineering

The best–worst method (BWM) is a relatively new multi-criterion decision-making (MCDM) technique that was developed to overcome some of the drawbacks of the analytic hierarchy process (AHP). Like its predecessor, BWM also relies on the strategy of decomposing complex decision problems into tractable sub-problems, while also providing a quantitative framework for synthesizing their results into a coherent global solution. However, BWM does not require the tedious pairwise comparison of all problem elements (i.e., criteria and alternatives). Instead, a small subset of all possible pairwise comparisons is used to formulate a linear programming (LP) model whose solution gives weights that are comparable to those generated by AHP. This feature allows more rapid and less error-prone elicitation of expert opinion to calibrate the decision model. However, there are few published works to date on the use of BWM in process systems engineering (PSE). We address this research gap by demonstrating the applicability of BWM coupled with simple additive weighting (SAW) using case studies on the selection of chemical reactors, plastic waste management processes, and 3D printers.