Methodology

This comparative analysis was performed by making use of Multiple-Criteria Analysis (MCA) . The MCA is a decision-making analysis that evaluates multiple criteria as part of the decision-making process. Therefore, it provides a systematic approach for ranking adaptation options against a range of decision criteria. The various criteria can be weighted to reflect the relative importance of different criteria. The weighted sum of the different chosen criteria is used to rank the options. MCA makes use of both quantitative and qualitative data in the ranking of options and, hence, allows the consideration of qualitative characteristics that can often be hard to quantify

To compare each process/technology a performance matrix is used. The performance matrix is a standard feature of multi-criteria analysis, in which each row lists the options, and each column outlines the criteria. The individual performance assessments are given a numerical value. For evaluating the performance of the process/technology, a linear additive evaluation model is used. The linear model shows how an option values against the many criteria and this can be combined into one overall value. This is done by multiplying the value score on each criterion by its weight, and then adding all those weighted scores together. The final product of the analysis is a final score assigned per criteria category which is reported in a spider-web diagram to compare the different processes/technologies.

The quantitative and qualitative data from each process/technology is assigned a numerical score based on a scale of preference for each criterion. The scale extends from 0 to 5, where 0 represents the least preferred option, and 5 is the most preferred option. All process/technologies’ criteria considered in this MCA fall between 0 and 5. Numerical weights are assigned for each criterion in order to emphasise the contribution of a specific criterion over others. The weighting factor is chosen based on island-specific contexts.

• The process/technology is a commercial application, or a technology in the final stage of development that is market-ready within the next 2 years
• The process/technology must not be a “prototype” at early stage of development 
• The process/technology must be able to convert/transform/use/dispose-of non-recyclable plastics*
• The process/technology must be suitable to be transported/developed and used in the SIDS 
• The process/technology should be versatile, suitable for small-scale production as well as large-scale, and able to process different types of polymers