Challenge for Planning by Using Cluster Methodology: The Case Study of the Algarve Region Bienvenido Huertas, José David Farinha, Fátima Oliveira, Miguel José Silva, Elisa M. J. Lança, Rui OBSERVE platform This study analyses the most appropriate methodology to make similarity classifications among the cities of the Algarve (Portugal) according to 105 sustainability indicators monitored with the Observatory of Sustainability of the Algarve Region for Tourism (OBSERVE). The methodology used to establish the similarities was the cluster analysis with 4 different approaches which reduced the dimensions of the data set: total approach, pillar approach, subject area approach, and indicator approach. By combining the approaches, a total of 620 different cluster analyses were performed. The results reflected that the data analysis approaches with less dimensions were those that performed the best groups among cities. In this sense, the approaches with a high number of indicators (e.g., the total or the pillar approach) were characterised by misclassifying cities in more than 30% of the indicators. Thus, the most acceptable cluster analysis approach was that with a low number of indicators. Through this approach, it was possible to make correct groups of the sustainability level of the cities of the Algarve. These results provided an appropriate methodology for the decision-making regarding the sustainability of a region and could be extrapolated to other regions to assess sustainability or environmental indicators. 2024-02-06T12:15:32Z 2024-02-06T12:15:32Z 2020-02-18 journal article https://hdl.handle.net/10481/88434 10.3390/su12041536 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional MDPI