## 4 Discussion and Analysis
### Challenges and Prospects  
In some countries, prefabrication is often described as a potential solution in the sustainable building process and in combination with the circular economy [158]. However, the downturn of the construction industry in the last two years has caused the industry to become marginally profitable, even with vicious competition. The main factors limiting the development of assembly M&E are that the industry is in a non-standardized situation, the process preparation time is too long, the factory labor productivity is low, the quotation reference is not uniform, the factory business is not saturated, the cost of the digital factory is too high, the factory mechanization is low, there is a lack of core competitiveness, the cost of the full-time installation team is too high, and the competition is high. To address these challenges. In September 2023, leading Chinese industry players co-organized an online forum conference with a semi-structured live interview on-site. The conference centered on the prospects of assembly M&E in China, and the participants consisted of seventeen organizations, including China Railway Construction Corporation, China Construction Fourth Engineering Bureau Corporation, and Chongqing University. The conference on the development of assembled M&E was discussed intensely, and a semi-structured on-site interview was conducted with the participants on the spot. The conference mentioned that because the current market for assembled M&E systems as a whole is showing a contraction and the industry is in a non-standardized state, there are no standards for the design of assembled plant rooms, no standard quotas, and no unified atlases and process standards. This can easily lead to process preparation time being too long, factory labor productivity needing higher, the offer needing a reference, and the overall low. In this regard, the conference advocated using information and technology to achieve customer-centric, comprehensive cost reduction and efficiency. Implementing design sharing, factory sharing, installation team sharing, a unified standard process, platform management, and pooling industry resources reduces design costs. Integrate design, business, construction, and factory resources to form a national group or alliance. Of the participants in the meeting, 14 units of representatives expressed support, accounting for 82%. There are three units with different opinions, accounting for 18%. Supporters believe that the formation of a national alliance can give full play to the advantages of each region, go to resource integration, and, through the sharing model, be realized with the university for cooperation in design, with the surrounding factories for integration of production, and with the intelligent equipment manufacturers. Secondly, it will be partially modularized, and only standardized parameters must be inputted to realize the drawing. Furthermore, through the sharing mode, it realizes the production of assembled machine rooms, boiler rooms, chemical enterprises, and other end equipment. The sharing mode can highlight the advantages of assembly electromechanical, forming an industrial standardization process, integrating materials and tools and other measured costs, and standardizing prices; these will be essential to future development. Finally, the development of assembly electromechanical is in line with the requirements of the national dual-carbon economy; forming a national alliance is more conducive to attracting the government's attention. Of course, some participants put forward different opinions. A prefabricated assembly machine room in the current market is not a necessary choice, belongs to something other than the necessary part of the non-standardized, and is easier to respond to the scene's needs flexibly. Another critical point is that the market demand for assembled rooms and standards could be more consistent, so it is unlikely to make all of them uniform and standardized.