## 3 Results Analysis
### Prefabrication Processing Stage
#### 3.7.1 Specific Analysis of the Prefabrication and Processing Stage  
Assembled MEP projects are one-offs, which can lead to a lack of standardization throughout the project's life cycle. Product design details are highly variable [74], which may lead to non-uniformity of equipment dimensions and more significant problems of plant standardization and replicability. As a result, [PERSON] et al. proposed a modular and standardized industrial plant design approach to solve this problem [75]. In addition, the replicability of the assembled M&E system is improved by focusing on the fabrication process of the pipe core [76]. Another area for improvement is that since the prefabrication is one piece, this leads to a high degree of difficulty in the inspection process after fabrication is complete. It has been shown that approximately 10% of construction rework costs are due to delays in detecting defects [77], which can lead to higher costs for prefabricated components. Therefore, automated techniques can be used to detect defects [78]. Quality management models can also be used to detect defects during pipe prefabrication using automated techniques such as photogrammetry and laser scanning [78], which can reduce the project's total cost by reducing manufacturing rework. Also, sensing technologies can be used for obstacle avoidance, productivity improvement, and material and equipment tracking [79]. BIM technology should also be introduced to monitor component prefabrication and pipe prefabrication [80]. By introducing these technologies, field defects will be significantly reduced, and the durability of components will be improved, resulting in cost savings and increased productivity [81]. Another point is that efficient communication and decision-making will significantly improve productivity. In this regard, MEP contractors should cooperate with manufacturing plants [55], and sequential coordination strategies are better than parallel strategies in coordination productivity [82]. In addition to efficient communication, it is also crucial for the optimal number of modules and system division points. As a result, an automated and efficient modularization algorithm can be used to determine the optimal number of modules and the system division point to ensure segmentation efficiency [61]. It has been shown that eliminating unnecessary framing methods in the upper part of the M&E system is most efficient when the coordination period is guaranteed, and adjusting the support spacing is also an economical design option [69]. Another critical factor limiting the development of assembled M&E systems, transportation, will have to be raised next. It has been shown that transportation is one of the factors limiting the development of prefabricated components [83], and the logistics of transportation [84] is a great challenge; heavy or large-sized M&E system components are very challenging to transport, and long-distance transportation or narrow and uneven roads can pose significant limitations. Prefabricated components should be as light as possible, as they sometimes need to be transported over long distances [85]. Therefore, embedded column connections can be used as an alternative to the traditional post-cast fixed steel load-bearing plates to reduce the weight and volume of the M&E system components to meet the transportation conditions [86]. Of course, the inclusion of BIM for on-site transportation management should also be considered [87]. Local policy documents should also be closely followed, as the impact of policies has a more significant influence on transportation logistics [88]. Another factor that affects the development of components is updating new materials. New technologies involving new materials have yet to receive a response from the community due to the lack of proper design guidelines. Therefore, the lack of evaluation criteria is likely the most critical deterrent to accepting new materials [89]. However, reading the literature, it is known that many materials developed by [PERSON] et al.