## 2 Methodology
### Comparison Criteria  
The systematic selection methodology of this paper consists of the comparison criteria. We identified the most frequent criteria based on the criteria defined in previous studies (see Section 1.2). Figure 1 illustrates them as a word cloud. Table 1 in the Appendix lists the underlying criteria. practicability (4), transparency (4), usability (4), data availability (3), efficiency concept (3), feasibility (3), indicators (3), integrated (3), integration (3), object analyzed (3), relevance (3), spacial scale (3), system boundaries (3), temporal characteristics (3), adaptive (2), aggregation (2), credible (2), efficient (2), environmental issues (2), exhaustiveness (2), focused (2), formalization (2), framework (2), impacts (2), intelligible (2), interdisciplinary (2), inventoried flows (2), life cycle thinking (2), overall purpose (2), participative (2), possible to communicate (2), reliability (2), rigorous (2), soundness (2), spatial characteristics (2), spatial focus (2), standardization (2), system modelling (2), systematic (2), top down (bottom up (2), acceptance (1), accurate (1), adaptability to global challenges (1), analytical potential (1)) approach character (1), approach type (1), availability (1), comparative (1), comparison basis (1), compatibility (1), completeness (1), comprehensive (1), comprehensive (1), considered aspects (1), considered environmental burdens (1), considered environmental media (1), consistency (1), cost effective (1) cross-sector(1) data subject (1), data type (1), ease of use (1), frequency being used (1), general public's understanding (1), indirect type (1), inherent quantities (1), inspiring (1), interpretation (1), investigated dimensions (1), legitimacy (1), maturity (1), multi criteriaassessment (1), multi criteria indicators (1), objectivity (1), perspective (1), possible to apply (1), product related assessment (1), purposive (1), quantitative vs. qualitative (1), reasonable (1), reference object (1), resistant against abuse (1), results aggregation (1), robust (1), scalable (1), scale (1), scale of impacts (1), site dependent level (1), spatial differentiation (1), spatial modelling (1), spatial variability (1), strategic (1), structure (1), sustainability dimensions (1), sustainability performance (1), temporal scale (1), temporal variation (1), time modelling (1), timing of impacts (1), type of impact assessment (1), type of modeling (1), unit (1), univority (1)  
To find the most suitable methods for analyzing and assessing cooling towers, we introduce a set of criteria by combining the ones from previous studies. To additionally clarify the dependencies, we assign the criteria to specific objectives. In addition, we define partial aspects for each criterion if appropriate. This way, each aspect can be categorized using three-valued logic; 'yes', 'no', or'maybe'. Figure 2 illustrates the structure of the comparison method. Table 2 summarizes the criteria-based comparison method with the objectives, criteria, partial aspects, and short descriptions of each aspect. Figure 1: Word cloud of the criteria defined for method comparison in previous studies; in parentheses is the number of studies that use these criteria, based on [12; 17; 18; 19; 20; 24; 27; 28; 29]. The criteria are sorted by overall objectives: green = ‘application area’, blue = ‘thoroughness’, and black = ‘usability, soundness’. The number in parentheses represents the times the criteria were used in the studies. Figure 2: Structure of the criteria-based comparison method and a classification example of whether a method fulfills the criteria and partial aspects (**left** column) and whether they should be fulfilled for the use case (**right** column). This results in suitability for each criterion and partial aspect, which, in the sum of all criteria, leads to the overall result. At first, the exclusion criterion is whether the _studied object_ corresponds to the application area of the method. The application areas are divided into 'process', 'product','service', and'region or sector'.