## 3 Results
### Thematic Analysis of Selected Articles
#### 3.2.2 Research Trends  
The conducted thematic analysis provides evidence on the focus of research on hard-FM. In Table 5, publications about maintenance management and FM procedures represent a total of 28.72%, followed by 17.02% of studies focused on data and information exchange topics and 14.89% dedicated to the sector's current developments and awareness in approaching the theme. The last emerging category analyses PA procedures with BIM-FM (12.77%). Some of the studies consider more than one area, and, in such cases, it was considered within more than one group.  
Concerning the maintenance management and facility management category, [PERSON] et al. [19; 20] show some evidence that a BIM model can be set at the centre of the management phase since it could be connected to other applications, databases or FM tools for moving the building to a smart building. [PERSON] et al. [69] concentrate on a maintenance database for maritime port infrastructures, and [PERSON] and [PERSON] [63] discuss, as the main topic, the improvement of facility management tasks enhancing coordination and communication in order to optimise costs and improve energy efficiency; this is the reason for why this publication is placed in multiple categories. Concerning BIM application to FM objectives, [PERSON] et al. [71] propose a system for managing unexpected FM activities for events or temporary situations. [PERSON] et al. [79] approach the theme of improving O&M through BIM and virtual reality, and [PERSON] et al. [32] focus on BIM-based corrective maintenance models. [PERSON] and [PERSON] [76] document some of the issues involved in adopting BIM for the FM stage. [PERSON] et al. [55] concentrate on a cyber-physical paradigm to guide O&M and the long-term refurbishment processes of buildings: real-time diagnosis, indoor comfort and health are some of the principal matters. Moreover, [PERSON] et al. [65] attempt to build a GIS query and QR code model to establish a visual management system for maintenance functions. As mentioned before, publications in the maintenance management and facility management category focus on energy management aspects [19; 55] or cost savings factors [19; 57; 63; 66] several times, which are also placed in the corresponding categories.  
The other relevant research objective when discussing BIM-FM implementation is related to information. For example, [PERSON] et al. [17] highlight the relevance and also the efforts of defining an Asset Information Model (AIM) and concentrate on analysing the handover process, extracting data and populating the models with O&M documents; then, [PERSON] et al. [42] and [PERSON] et al. [35] propose information frameworks and protocols for FM, AIM and Organizational Information Requirements (OIR); another contribution toward information through BIM within the built environment field is that of [PERSON] et al. [62] discussing heritage BIM. Concerning data security, another topic is that of  
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blockchain application to AEC information management systems [46]. Finally, IFC [61] and Cobie [21,80] are discussed in relation to standardisation and interoperability.  
Looking at the PA category, it is underlined that some of the studies are linked to those represented in the first step of thematic analysis since these do not address a specific building typology but describe BIM-FM implementation in the PA management context in general.  
In addition, the research trend analysis shows evidence that more recent articles that have focused on COVID-19 BIM management, combined with occupancy control and flow management, is a new area; indeed, these are presented in recent publications [19,20,28,34]. In light of the current context, these subjects promise to have a central role in future research work investigations.