## 5 The Implementation Path of the ICSPB-IoT
### Discussion  
In essence, building information management can be regarded as a process of driving intelligent construction based on available information. The existing industrial intelligent systems generally include three dimensions: lifecycle dimension, system hierarchy dimension and intelligent feature dimension [49]. The ICPSB-IoT is an integrated decision-supporting system for full lifecycle data collection, processing, and analysis of prefabricated buildings. The decision-making service is related to the specific service requirements of the engineering application. For different users, the content of the service and the required decision-making subsystem are also different [50]. In comparison, an ICSPB-IoT is more comprehensive, which is suitable for the needs of the government, contractors and owners. The tripartite project level engineering information is mostly derived from the PIIC and IBD to ensure the unity of the data source. Meanwhile, SCOs at the unit layer of ICSPB-IoT can enhance the functionality of the BIM [27]. The SCOs can collect information, in a timely manner, on the physical status and surrounding environment with awareness and communication, which could actively, frequently, and accurately synchronize construction and production information with BIM elements, laying the foundation for the interoperability of the ICSPB-IoT. In addition, the main systems and subsystems of ICSPB-IoT are interconnected, with the functions of receiving/transmitting, controlling, debugging and storing. They can be regarded as network \"nodes\" and extension components of the construction IoT. SCOs, as construction resources augmented with AI, are the basic components of the construction IoT [27]. In the IoT paradigm, the connections of SCOs, subsystems and systems can be established based on specific mechanisms or protocols [7]. Once the network system is established, as SCOs continuously sense, record and share real-time information, the subsystem connected to SCOs will also be activated in the ICSPB-IoT. Eventually, the ICSPB-IoT network composed of subsystems can remain active. The IoT shared services at all stages (e.g., integrated design, lean production, transparent transportation, visual assembly, and intelligent building) can be realized based on the ICSPB-IoT between different parties.  
It is foreseeable that ICSPB-IoT will gradually achieve industry standardization and enter the market in the future, forming a complete ecosystem. However, there are still many challenges to overcome. The first challenge is interoperability. System programs in different environments should interoperate and exchange information at all layers, including the unit layer SCOs, the production line layer subsystem, the working space system, and the enterprise layer systems. The intelligence of the system largely depends on the ability of information exchange between them. The highly dispersed nature of buildings leads to the increase in system diversity, and it is tough for a single enterprise to guide the industry to achieve technological progress [51]. The device deployments are usually decentralized and mixed, which is a potential challenge for achieving the interoperability of an ICSPB-IoT [52]. Secondly, for the construction industry, it has been slow in the adoption of new technologies. Before receiving obvious benefits, companies will particularly hesitate to invest in this area [53; 54]. This conservative approach will hinder the study and adoption of ICSPB-IoT. Additionally, an ICSPB-IoT is a complex system with multiple subsystems. As the number of devices connected to the communication network increases, the security and privacy issues of the system become potential challenges [52]. The security of the IoT system depends on the technology, protocols and security mechanisms implemented by the system and equipment, and any system may be subject to certain types of attacks [55]. Strong security standards and mechanisms should be developed for ICSPB-IoT in time to respond to emerging threats.