The selection of saltwater desalination technology using new measurement alternatives by a combination of angle and distance (MACAD) method: a case study

Saltwater desalination is a key solution to future water scarcity. Due to multiple influencing factors, selecting appropriate desalination technologies is challenging. Multi-criteria decision-making (MCDM) methods assist by systematically evaluating and ranking alternatives. Consequently, this article proposes Measurement Alternatives by a Combination of Angle and Distance (MACAD) approach to select the most suitable water desalination method site in Qeshm, Iran. In the proposed method, each alternative is evaluated and ranked based on a geometric measure that combines its distance from the negative ideal point and the angle between its corresponding vector and the reference vector connecting the ideal to the anti-ideal solution. This study is the first to incorporate the angle between alternative vectors into MCDM modelling. Although demonstrated through a desalination case study, MACAD is a flexible and scalable decision-making method suitable for various complex problems involving multiple criteria and alternatives. A real-world case study on selecting the most suitable water desalination technology is presented to demonstrate the performance of the proposed method. The results of this study indicate the choice of electrodialysis as the most appropriate technology. Two validation strategies are employed to assess the reliability and robustness of the MACAD method. The first involves comparing MACAD results with those of conventional MCDM methods, revealing a high level of correlation. The second consists of a sensitivity analysis based on the Criteria-Oriented Modification Sensitivity Analysis Method (COMSAM), which perturbs multiple criteria and confirms the method’s stability through low relative variation and consistent score intervals.