# Integration of BIM Tools for the Facility Management of Railway Bridges
## 3 Literature Review  
### Inspection and Monitoring of Railway Bridges  
The inspection of civil works involves the assessment of the physical and functional conditions of civil infrastructure systems such as buildings, roads, bridges, etc. Historically, it has been overshadowed by the construction phase of the same work [20; 57], despite the fact that the operation and maintenance stage is the longest phase in the entire life cycle of AECO industry works [58]. Generally, infrastructure monitoring is carried out periodically through visual inspections, which tend to be prolonged, requiring the interruption of the regular functioning of the system. Consequently, these procedures are limited in terms of time and access requirements [6; 20; 21; 22; 23; 27]. Additionally, asset monitoring programs are necessary due to uncertainties in environmental and mechanical conditions, material properties, and load history, as in the case of a bridge [59]. Therefore, monitoring activities are essential to maintain public and structural safety, trust, investment, and the durability of assets to ensure they reach their expected lifespan [3; 5; 21; 22; 37; 38; 60].  
In railway bridge inspections, although new non-destructive techniques have helped update traditional inspection and maintenance methods [61; 62; 63], these methods still primarily rely on visual inspection. Being conducted visually by humans, the results are subjective, affecting their reliability and precision since they directly depend on the experience and skills of the personnel, which can vary depending on the inspector [20; 21; 22; 25; 26; 29]. Other limitations of current methods include the dispersed nature of the data collected from monitoring activities across different data sources, which can lead to information loss. Moreover, maintenance planning is often performed at the element level, sometimes without a clear understanding of the entire infrastructure, being overly simplified, and the data entry into systems lacks a clear visual interface [26; 30; 43; 44; 64].  
Additionally, in current methods, it has become common to perform these tasks only when real emergencies occur, adopting a reactive approach. This practice is ineffective since reactive maintenance tasks can cost three to four times more than the same repair activity if implemented as preventive and planned maintenance, which consists of simple but continuous actions over time [39; 40; 41]. In bridge management, previous research has developed approaches to determine the optimal timing of asset inspections and predicted future interventions to preserve the structural health of the bridge. However, these methods generally adhere to strategies that focus on understanding the repercussions of bridge failure, maintaining a reactive logic [41; 65].  
Since the failure or poor planning of asset maintenance tasks can lead to high safety, economic, and social costs, the AECO industry has leveraged technological advances in software, frameworks, and application tools to update asset management methods throughout their life cycle, particularly in the automation of facility management activities to improve work efficiency during the operation and maintenance phase. This is because more complex modeling tools are needed to model asset degradation and support the management decision-making process [22; 33; 35; 42].