## 4 The Operating Mechanism of the ICSPB-IoT
### Operating Mechanism  
For the design stage of an ICSPB-IoT, the goal is to coordinate design, manufacturing and construction, as shown in Figure 3. Firstly, according to the owner's needs, a function and performance-oriented approach should be adopted by the designer to develop the design model. Based on this model, a force analysis and collision detection through software (e.g., Glodon and ANSYS) are conducted to generate parameters for the manufacturing and construction in the ICSPB-IoT. Then, manufacturers need to conduct a comparative analysis between the production information of prefabricated components (e.g., materials, production processes, components quality) and design parameters to ensure quality in the manufacturing process. Meanwhile, the constructor should transmit the construction information on-site (e.g., location information of mechanical systems, pipeline and equipment, on-site space collision, on-site construction and design conflicts) comprehensively and accurately in real-time to the integrated design subsystem to facilitate the designer to make technical changes in time. In the environment of the IoT, the information interaction between the entire design, manufacturing and construction processes is realized, which ensures the integrated construction approach of design-manufacturing-assembly. Figure 2: The formation of the ICSPB-IoT “information network”. In the component production stage of an ICSPB-IoT, in addition to the quality control system of prefabricated components for collaborative design, manufacturers also need to have a production scheduling system to achieve lean production goals. For example, a lean production system of precast concrete components has been developed by [PERSON] et al. [28]. In the context of the IoT, RFID, sensors and other equipment can record the entire process of component production, collecting information in each production process. Then, the quality inspection information of prefabricated components will be transmitted to the IBD, to realize the coordination between upstream design and downstream construction process. In addition, the construction site and workshop information related to the inventory, production process, and resource configuration are integrated into the component production planning scheduling subsystem. Based on this, eight wastes (e.g., overproduction, defects, motion, material movement, waiting, excess inventory, overprocessing, correction) can be eliminated, so as to achieve the goal of maximizing benefits, as shown in Figure 4.  
Figure 3: The operating mechanism of ICSPB-IoT in the design stage. In the transportation phase, the transparency of real-time information should be achieved. Logistics trucks should be equipped with GPS positioning systems, RFID, sensors and wireless communication systems. Once the electronic waybill is transmitted to the component transportation scheduling management subsystem, the order information will be matched with the information in the cataloguing vehicle, GIS and E-Map to find the best delivery scheme. In addition, in the transportation process, the RFID tag of the vehicle, the building component RFID tag and the driver ID card are connected to the IBD, so that the contractors can obtain the real-time information of vehicle number, driver, cargo list, and driving route. More importantly, the ICSPB-IoT can calculate the estimated arrival time accurately, and then the on-site management staff can initiate the unloading preparation work (e.g., lifting appliances and personnel arrangements, site cleaning, storage space arrangements) according to the arrival time of components to save time. The on-site hoisting stage gathers almost all participants, including the manufacturer, transporter, supervisor, material supplier, constructor, officer and owner, so the information exchange between various parties is particularly important in this stage.