Table 2.

Different MCDA processes with addressed Research Questions (RQs), recommended and applied MCDA methods for remediation alternatives prioritization in this case study.

Decision-making features	MCDA Process 1 (RQ 1, 4, 5)	MCDA Process 2 (RQ 1, 2, 4, 5)	MCDA Process 3 (RQ 1, 3, 4, 5)	MCDA Process 4 (RQ 1, 2, 3, 4, 5)
1. Desired outcome	Complete ranking driven by a score
2. Criteria structure	Flat structure of criteria	Hierarchical structure of criteria	Flat structure of criteria	Hierarchical structure of criteria
3. Evaluation of the alternatives on the criteria	Qualitative measurement scales for four criteria, assessed on a five-point scale, scoring from very low to very high. One criterion (i.e., costs) is measured on a quantitative scale ($).		Qualitative measurement scales, assessed on a five-point scale for four criteria (i.e., excluding costs), scoring from very low to very high. Uncertainty in evaluating the alternatives using a precautionary assumption of one worse performance (e.g., assuming positive polarity, if the score was 2, it can also be 1). One criterion (i.e., costs) is measured on a cardinal scale with uncertainty in the form of −30% ≤ deterministic value ≤ +50%.
4. Compensation level between (sub-) criteria	Null
5. Weights of the criteria	Equal weights
6. Robustness analysis	No → Single recommendation		Yes → Stochastic characterization of trends
MCDA methods recommended and applied	PROMETHEE II	PROMETHEE II for hierarchical criteria	SMAA-PROMETHEE II	SMAA-PROMETHEE II for hierarchical criteria