163 © Springer Nature Switzerland AG 2021 E. Estevez et al. (eds.), Smart Cities and Smart Governance, Public Administration and Information Technology 37, https://doi.org/10.1007/978-3-030-61033-3_8 A Methodology for Participatory Planning of Smart City Interventions Charalampos Alexopoulos, Loukis Euripidis, and Yannis Charalabidis Abstract The development of smart cities is a highly diffcult undertaking, which requires participation and cooperation of several stakeholders, both in its planning, due to the multiplicity of possible smart city interventions available as options, and also in its implementation, due to its high complexity. Especially for planning (selecting and prioritizing) specifc smart city actions to be implemented it is neces- sary to combine knowledge: (1) on one hand from the university and the industry, concerning the possible smart city interventions, the capabilities they can offer in general, as well their diffculties and challenges; (2) and on the other hand from the municipalities and the citizens, concerning the ‘real-life’ benefts and value that these possible interventions can actually provide, and their potential for addressing specifc challenges, problems and needs of modern cities. However, there is a lack of sound methodologies for this required participatory planning of smart city inter- ventions. This chapter contributes to flling this gap, by presenting a methodology for this purpose. It is based on a detailed taxonomy of possible smart city actions, which we have developed through a review of relevant literature, representing knowledge that has been developed in this area by the university and the industry, who can be viewed as the smart city actions’ supply side. This taxonomy is used for collecting assessment data from municipalities as well as citizens concerning these possible smart city actions, which incorporate relevant knowledge and preferences of municipalities and citizens, who can be viewed as the smart city actions’ demand side). Our methodology includes three layers of processing the above municipali- ties’ and citizens’ assessment data, which reveal: (a) the perceptions and priorities of these two important stakeholders concerning smart city actions (layer I–II respec- tively); and (b) points of convergence as well as points of divergence between them (layer III). These enable a rational participatory planning of smart city interven- tions. Our methodology has been applied in the context of Greece: assessment data concerning the above possible smart city actions have been collected from 144 Greek municipalities and 500 citizens, and their processing has led to interesting conclusions, which can be quite useful for planning the next steps of smart cities’ development in Greece. C. Alexopoulos (*) · L. Euripidis · Y. Charalabidis University of the Aegean, Lesbos, Greece e-mail: alexop@aegean.gr; eloukis@aegean.gr; yannisx@aegean.gr