## 4 Discussion and Final Remarks
Then, the last years have been characterised by an increase in literature reviews aiming to establish knowledge on the status of BIM-FM integration in the public sector. The results on building typologies underline that a generic description of public owners and administration involvement in BIM for FM is predominant, which assesses that the subject is approached at a general level. This category is followed by educational buildings that stand for campus, universities and infrastructural buildings, including maritime ports, airports and transport buildings in general. Concerning universities, the outcome is strongly related to the fact that these are linked to the academic context, which is, at the same time, a context of research and experimental studies. Thus, multiple publications are carried out on educational buildings, since researchers have the data available, and the work could be directly tested. Studies on infrastructure and hospital buildings, which is the other group following the first ones, prove that these categories require planned management and that their maintenance is of primary importance. In particular, this fact could be seen as a reaction to the COVID-19 pandemic and (especially in the Italian context) to infrastructural disasters, such as the collapse of Ponte Morandi or railway accidents. Results on the research focus highlight the predominance of work on maintenance management or facility management procedures in operating building services. This topic has the highest percentage of publications in the field and a constant behaviour over time. Another prevalent topic that has been steady during the years is data and information exchange. This subject has always been predominant when investigating BIM for FM. Moreover, the other category following the first two groups publications about general public sector awareness concerning BIM-FM implementation. This group includes works on the current industry knowledge; most of the studies in this class correspond to those embedded in the \"Generic\" one in building type analysis. The analysis has also pointed out that a rising research trend is coming to light: COVID-19 BIM management can be considered to be a relatively new trend discussed in studies from 2020. Looking at the last part of the research based on BIM-FM implementation from three clusters' perspectives, it is evident that this subject has been mainly addressed until now as a process. Notwithstanding that some publications propose new platforms or technological solutions for this implementation, the core of the research is still presented like a process, which expresses it through the integration of technologies. However, the study does not have a prevalent technological orientation since it is described through a process framework. Therefore, BIM-FM implementation in the public sector is described as a methodological process. At the technological level, the limited number of publications underline that, at the moment, the systems are not fully capable of managing the overall FM phase. The novelty of the subject and the overall predominance of processes propositions might explain the scarcity of the challenge and challenge's description, commonly identified in practical applications of BIM-FM implementation. Thus, publications usually prioritise benefits and positive matters rather than problems. The central implementation aspect can be summarised through this issue: the lack of standards. This is strongly linked to data and information exchange. Therefore, efforts should be taken to define a common approach for managing BIM in the FM field in the public environment. Regarding the topics that the literature is silent about, the review showed an absence of quantitative information concerning organisational problems related to FM within the FM literature that can be used as a baseline for a meaningful analysis of the results from various pieces of research.