# Interoperability Analyses of BIM Platforms for Construction Management
## 1 Introduction  
The US National BIM Standard (NBIMS-US) defines BIM as \"a digital representation of physical and functional characteristics of a facility\" [1]. In other words, building information modeling (abbreviated and commonly called \"BIM\") is a virtual platform where graphical and nongraphical data are produced, visualized, processed, analyzed, exchanged, shared, and maintained in the architecture, engineering, and construction (AEC) industry. The approach on which BIM is based is that before physically building the structure, it is built in a virtual system as a \"digital twin\" of the physical structure itself. In this way, problems can be anticipated, simulated, and worked out before the execution phase [2]. BIM is not only a software platform used for modeling a structure but also a process and approach that allows us to follow the design of the project and the life cycle of the structure in a virtual environment in a comprehensive way from the beginning of the concept. Recently, construction industry technology has started to evolve from conventional 2D methods to 3D platforms by the commercial use of BIM tools. The increase in demand, initiatives, and collaboration of different disciplines in the AEC industry and the adoption of BIM platforms for design entails transferring data between different users from a variety of trades that have started to exploit BIM platforms. In 2018, research from China [3] revealed how BIM tools are used by different disciplines in the AEC industry. These tools are most frequently used at the design stage for model design (25.9%) and model checking (24.8%), respectively. These are followed by quantity take-off (16.3%), constructionsimulation (13.8%), construction management (7.6%), and visualization and roam (6.2%). The tools are less frequently used for terrain (2.1%) and prefabrication (2.3%). Only a small number of the projects used the tools for preservation (0.5%), operation and maintenance (0.5%), and refurbishment (0.2%). A more recent paper [4] presented the results of a similar investigation, referring to the use of BIMs for educational facility projects in the United States. Considering five categories of stakeholders like architects, contractors, structural, site, and MEP (Mechanical, Electrical and Plumbing) engineers, the major BIM applications were 3D visualizations, automation of documentation, and clash detection. Depending on the discipline's scope of work, the architects and site engineers thought that the use of BIM was providing value in the design phase of the project while the structural engineers and contractors saw the benefits of BIM use in both design and construction phases of the projects. MEP engineers thought that BIM use was almost equally valuable in all the project phases. In [5], a more general and global investigation on the status of BIM adoption worldwide is presented. Since there are many different disciplines involved in this industry, BIM-based tools are implemented and used to perform a large variety of tasks, i.e., creating 3D geometry of buildings, structural analysis, cost estimation and planning, and operating the facility [6]. Generally, working with different disciplines also means working with different types of software packages and file formats and extensions. Today, there are several exchange formats frequently used in the AEC industry, such as DXF, DWG, XML, SAT, STP, 3 Ds, and IFC or CIS/2 [7]. Moreover, there is no single software able to perform all these tasks; hence, the use of more than one single software is a must. Software packages in the market do not support or have limited support for exchanging data. Thus, when performing analyses requiring the transfer of data from one tool to another, due to the incompatibilities in file exchange, an additional effort is generally required. In addition to this, also throughout the exchange operations, the different file format versions must be taken into account, even if the file standards are the same.