## 4 The Operating Mechanism of the ICSPB-IoT
### Operating Mechanism
For instance, in order to ensure the quality and safety of construction, the GMTS needs to perform an intelligent analysis of field operations based on the quality and safety database. Meanwhile, besides supervising the site, the supervisors also need to obtain information related to the building quality for setting up the digital engineering product in the DISEP. Besides, the constructors should not only ensure quality and safety, but also accurately control the resource management of the construction site and production plan activities to pursue maximum benefits. The construction site involves the information collection, processing and interaction of high volume, multisource and complex characteristics, which means effective information interactions among project participants are difficult. The ICPSB-IoT offers the possibility to address this issue. First of all, supported by RFID, sensors, GPS and other IoT technologies, the system can transform the construction resource elements into intelligent construction objects (SCOs) that have the characteristics of awareness, communicativeness and autonomy [27]. In addition, the entire information is connected to the construction site resource element management subsystem in real-time. The construction resources are reasonably allocated and scheduled with the principle of cost minimization. Then, the information in the upstream stage (e.g., fabrication process, structural performance, transportation time, etc. ), as well as the information on-site (e.g., component quality, hoisting process, node connection,  
Figure 4: The operating mechanism of ICSPB-IoT in the component production stage. material, etc.) are collected and transmitted to the project quality traceability subsystem by using the data transmitter. This facilitates constructors to carry out intelligent on-site management. Moreover, the safety supervision information of on-site workers, including the working height, the wearing conditions of the seat belts, helmets and safety nets, are transmitted to the engineering safety early warning subsystem in real-time to reduce the occurrence of safety accidents. Finally, these subsystems are connected to the GMTS and the monitoring and early warning system. Once quality problems and hidden safety hazards are discovered, the system will immediately activate the alarm. The entire on-site assembly process is in a visual state. In addition to the constructors' comprehensive management and control of the construction process by using the systems, the government and supervisors can also use the systems to promptly correct inappropriate behaviors that do not meet standards during the construction process, minimizing losses and ensuring the quality. Concerning the final product delivery stage, its operation mechanism is shown in Figure 5. The supervisors obtain the engineering data corresponding to the physical building from the IBD in real-time, and then the digital engineering products are completed synchronously in DISEP. The constructor uses RFID, sensors, artificial intelligence and other IoT technologies to connect the physical engineering products with the digital engineering products in an all-round manner, including physical space location, quality status, usage, operating status and other information of SCOs, which enables prefabricated buildings to become smart buildings.