*2.1. Assembled Supply Chain Risk Identification*

The prefabricated building supply chain is guided by the needs of the owner, and the general contractor is responsible for the coordination and scheduling of various node enterprises, such as the designer, manufacturer, transportation, and assembly party, to meet the needs of the owner, the general contractor, and the government. Different stakeholders face different risks in the five stages of design, procurement, manufacturing, transportation, and assembly, and at the same time, each risk is mutually restricted, and the problem of one problem will drive the entire supply chain to have a linkage effect. As the first step in the construction activities of various stakeholders, the formulation of the plan directly affects the work arrangement of the subsequent procurement, manufacturing, transportation and assembly stages; the raw material standards procured by the owner and general contractor also affect the component manufacturing and later assembly work; the manufacturer's control of the delivery time and quality of prefabricated components will affect the transportation arrangement and assembly quality; as transportation is an indispensable part of construction activities, its safety will also affect the progress of engineering assembly. Based on this, the relevant literature at home and abroad and prefabricated building accidents are analysed and summarized, and the risk factors of the five stages of design, procurement, manufacturing, transportation, and assembly and the perspective of the external environment are preliminarily formed, and then experts in the field of prefabricated building are invited to summarize the relevant risks based on the characteristics of the prefabricated building supply chain [30–34]:


#### *2.2. Risk Transmission Mechanism of the Prefabricated Building Supply Chain*

At the planning level, the accuracy of the target of the plan affects the time of purchasing materials and the transportation time of products, and the standards for manufacturing will also be limited. At the purchasing level, the quality grade of purchased materials limits the assembly results and the quality of manufactured products. At the manufacturing level, the time of manufacturing products and the delivery time limit the transportation of products, and the qualified rate of manufactured products has an impact on assembly. At the transportation level, unreasonable transportation planning leads to changes to the supply chain structure and delays the progress of the project. At the level of assembly, the quality of assembly parts is unqualified, which cannot meet the assembly standards and delays the construction period; at the same time, it may lead to accidents in production safety. At the external risk level, sudden weather changes delay the progress of supply chain projects, and some policies issued by the government restrict parts of the products, which will have an impact on the subsequent manufacturing of products and assembly materials. The risk transmission mechanism of the prefabricated building supply chain is shown in Figure 1.

**Figure 1.** Risk transmission mechanism of a prefabricated building supply chain.

#### **3. Establishment of the Model**
