## 3 BIM and DTs--Latest Development Trends and Challenges
### Standards, Requirements, and Approaches  
A novel approach is required, particularly in light of the standards and guidance documents published in recent years that regulate the possibilities and rules for selecting BACS functions and smart services dedicated to buildings. One of the significant and widely applicable standards regulating the principles of utilizing BIM in the organization of building functionality is the ISO 19650:2018 \"Organization and digitization of information about buildings and civil engineering works, including building information modelling\" [96]. It provides a set of guidelines for the management of a building throughout its life cycle. Moreover, the document highlights the potential of BIM as a valuable tool to enhance the utilization of facilities, the operational efficiency of buildings, and the effectiveness of design processes. This standard contains several sheets covering detailed issues: (i) the flexibility and versatility that characterize the wide range of potential BIM strategies, (ii) the requirements for information management in the context of the delivery phase of assets and the exchange of information within it using BIM, (iii) information management in the form of a management process in the context of the operational phase of assets using BIM, (iv) the detailed process and criteria for decision making when performing an information exchange as specified in the ISO 19650 series to ensure the quality of the resulting project information model or asset information model, and finally, (v) the principles and requirements for security-conscious information management for BIM as well as for the security-conscious management of sensitive information that is acquired, created, processed, and stored as part of any other initiative, project, asset, product, or service. As the analysis of these issues demonstrates, the implementation of BIM in modern buildings requires advanced technological tools--not only software but also hardware. Consequently, the authors of the concept of a seamless marriage of BACS technologies, IoT, and cloud services propose that this could be a potential platform for the effective design of BACS functions and extended automation networks in buildings, as well as for the organization of FM tasks during its operation [97]. As an illustration of the initiatives that have already been implemented in this field, in particular aimed at the universalization and unification of information about buildings for BIM systems, it is possible to provide the development of an open standard for formatting COBie (Construction Operations Building information exchange) information [98; 99]. It is a key part of the digital transformation of construction, which enhances building management and reduces costs. This open standard provides a set of rules for universal data exchange about the building that underpins the DT. It simplifies data exchange between  
Figure 4: The concept of an integrated BIM and DT platform with BACS and IoT support in buildings [26; 27; 69]. systems such as BIM, CMMS (computerized maintenance management system), and BMS. Moreover, it ensures a good level of data quality and consistency while facilitating a faster response during a crash. However, it should be noted that in the case of BACS, in particular the open standards of KNX, LonWorks, and BACnet building automation, standard data objects that are commonly used in the industry are already defined (e.g., SNVT--standard network variable types for LonWorks and DPT--data point types for KNX). Moreover, functional profiles have been defined for these standards, which determine the principles of implementing the most important automation functions, using standardized data types. Therefore, when trying to integrate the BIM and DT environments as tools for the design and maintenance of BACS and BMS, it is essential to consider these standards, along with their potential for developing new, universal semantics.