## 4 BIM in the Facility Management of Infrastructure  
Considering BIM as a digital representation of the infrastructure along its lifecycle [4, 134] or as a central information repository [4, 20, 135, 136], this methodology has been commonly associated to the design and project phases. Nevertheless, BIM eases the decision-making process in all project phases [137] of any infrastructure typology such as bridges, railways [138], buildings or roads [139, 140]. However, the initial BIM implementations have been traditionally related to the design phase in the edification sector. Over the years, this tendency has been turning into new BIM implementations that are deep enough to create new BIM concepts such as BrIM or Civil Integrated Management (CIM). Newterms of BIM show the expansion of this methodology through the edification sector and design phase to the Civil Engineering sector, construction stage or infrastructure FM. The FM concept is defined by multiple authors; i.e., [PERSON] defines it as the concept of its application creating internal value for the infrastructure users [141]. [PERSON], [PERSON] and [PERSON] define it as the process of associating the main building functions with all the services hosted in it [142]. This concept gains importance in special and complex infrastructure where multiple services are provided to the users. Airports, hospitals and universities are examples. [PERSON] and [PERSON] found that the total cost of the FM ranges from 5% to 15% of the total university budget [143]. Traditional techniques of FM inside public infrastructure are still being implemented currently. Lack of data digitalisation or excessive based-paper format information are examples of it. Nevertheless, innovation and digitalisation are expanding worldwide. Local governments are more aware of the importance of those concepts and support its implementation in their territories through national plans such as Digital Spain 2025 [144], which promotes the digitalisation of the public heritage. Currently, the complex social demands on infrastructure assets, as well as the high expectations of productivity and special service needs [145,146], imply a total improvement of traditional FM techniques pointing to the concept of smart infrastructure. Reduction in maintenance costs and damage, increasing the quality and value of service and security improvements are common benefits related to the smart infrastructure concept [147], which is defined by [PERSON] et al. as the infrastructure which could self-govern or make decisions without human intervention [145]. In addition, FM data and information can be managed with the aid of information systems or digital platforms such as Computerised Maintenance Management Systems (CMMS), Enterprise Resource Platforms (ERP), Electronic Document Management Systems (EDMS) and so on. BIM is a commonly used tool to achieve the mentioned infrastructure digitalisation [148, 149, 150], and it could be considered as a correct first step to reach the smart infrastructure concept. Many publications detail the BIM implementation into the FM sector. The transport infrastructure usually supports continuous ageing and deterioration, while O&M costs rise, which directly impact on state budgets. In this literature review, publications on transport infrastructure management are featured. Most of the recent literature shows that the use of BIM together with other information technologies can support a more reliable, sustainable, and safer transport network while reducing maintenance costs and risks [151]. The implementation of Industry 4.0 technologies in FM enables maintenance planning, optimising available resources and facilitating the decision-making process [152]. At the same time, information, which comes from several sources, is not fully integrated among all considered systems. This leads to processes and procedures that are not yet optimized. For instance, this can be referred to a limited use of open standards (e.g., IFC), open systems and standardised libraries.