# Multi-Agent Simulation Approach for Modular Integrated Construction Supply Chain
## 1 Introduction  
The transition from traditional on-site construction methods to off-site construction signifies a pivotal evolution in the construction industry [1]. Off-site construction (OSC) encompasses several levels of prefabrication, each offering distinct advantages in terms of efficiency, delay, cost, and environmental impact [2]. The simplest form, construction based on prefabricated components (PCs), involves the off-site manufacturing of basic structural elements like beams, columns, and slabs, using materials such as reinforced concrete, steel, and wood. This method, while lessening some on-site activities, still requires significant on-site construction efforts [3]. More advanced is panelized construction, where major structural components such as walls, floors, and roofs are produced in factories as prefabricated panels [4]. These are then transported to construction sites for assembly, improving the construction process by reducing the construction timeline and on-site labor requirements. Further along the spectrum lies modular construction (MC), where entire sections of a building, such as hotel rooms or classrooms, are fully constructed off-site in a factory setting [5]. These modules are then transported to the site and assembled into the final structure. This method allows for building components to be stacked, joined side by side, or layered, depending on the architectural design. At the top of OSC technology is modular integrated construction (MiC) [3]. MiC not only employs the benefits of modular construction but also integrates mechanical, electrical, and plumbing components along with interior finishes during the factory phase. This integration significantly expedites the overall construction process and minimizes the need for on-site installation, offering thehighest level of prefabrication. Given its comprehensive approach, MiC presents a unique set of logistical challenges, particularly in the transport of these fully integrated modules. Figure 1 illustrates the distinct stages of OSC. This progression from the simplest form of prefabrication, using basic structural components, through more complex modular constructions highlights the incremental advancements in prefabrication techniques that enhance efficiency, reduce delays, and mitigate environmental impacts across the construction industry. Recent studies in MiC and construction supply chain management (CSC) have highlighted a series of significant challenges necessitating in-depth research [3; 6; 7; 8; 9]. These works underline the critical need for resilient CSC frameworks capable of mitigating impacts from disruptions, a common feature in today's dynamic construction environments [10]. Enhancing CSC resilience relies crucially on robust information sharing and collaborative efforts among all stakeholders, including suppliers, manufacturers, transporters, contractors, and project managers [6]. Advanced technologies, such as Building Information Modeling (BIM) and Internet of Things (IoT), are essential throughout the entire building lifecycle, including the design, construction, and exploitation phases [11]. BIM provides detailed digital models that enhance decision-making, coordination, and efficiency at each stage [12]. IoT complements BIM by enabling real-time data collection and communication among devices, which allows for the dynamic monitoring and control of construction processes [13]. Additionally, IoT allows for the continuous monitoring and management of building systems in the exploitation phase (e.g., energy use, environmental conditions, and equipment status), ensuring optimal performance and proactive maintenance [14]. Together, BIM and IoT support the creation of digital twins--virtual replicas of physical assets--that offer comprehensive insights and predictive analytics to optimize both construction and post-construction phases [11; 13]. In the context of MiC, these technologies are particularly impactful.