# BIM-Based Management System for Off-Site Construction Projects
## 3 Requirements Analysis for System Development
### Elements of OSC Project Management
#### 3.2.1 Project Management Requirements  
The OSC project supply chain must be systematically and effectively managed. Specifically, the system must be able to facilitate synchronized and timely production along with integrated data-based management. OSC projects in each domain, such as factories, logistics, and construction sites, must be managed through integrated data-based management, by linking the data related to each area. The data can be linked and integrated through BIM-based parametric design technologies. Furthermore, the system must have information sensing and synchronization functions to track the status of the components in real time through the factory-logistics-construction site flow to achieve the JIT production goal of the OSC projects. In OSC projects, information for each management area is continuously generated and exchanged in real time across the areas. Therefore, information related to the components, the basic unit in OSC projects, must be appropriately managed. In conclusion, from the SCM viewpoint, the management system must involve the following functions. * BIM-based design-production-installation information linkage and integration;
* Zone plan and installation order management;
* Importing and integration of design and engineering models;
* Sensing and synchronization of the product status (production/stocking/shipping/transportation/entry/assembly);
* Product location tracking. Moreover, the OSC project management system must take into account the characteristics of each stage of production, logistics, and installation. Offsite production distributes the management points of the OSC projects to factories, logistics, and construction sites. Therefore, in addition to the finished products, the overall factory production, including the facilities, equipment, and resources, must be managed. Furthermore, logistics management from production to constructing site introduction is required. First, the OSC project management systems must effectively respond to distributed management points by establishing a plan which is suitable for the characteristics of each stage of the OSC project and has the ability to grasp the current status. The production phase requires the visualization of the following points for timely management: production, storage, and the inventory management of the components and their shipping for onsite delivery. Additionally, in the logistics phase, transport information such as that of the delivery products, vehicles, and road conditions must be considered. In the installation stage, the construction status of the components must be monitored. The management system must also be able to manage and support the overall plant production. Production in a factory is typically based on the drawings confirmed at the design stage. Therefore, it is crucial to link and manage the product and mold drawings (if necessary) with design drawings. In addition, offsite manufacturingmust be performed according to the onsite installation schedule. Accordingly, the system requires a planning function to satisfy the onsite installation schedule by reflecting variables such as the product design, raw materials, and lead time. Finally, the project management system must track the production status, inventory, shipment, transportation, entry, and installation of components. The manufactured components are stocked until requested for delivery by the site. Because the manufactured products have a higher volume, weight, and lead time compared to those in traditional projects, strict inspection is required at every stage. Additionally, digital-based management must be implemented to ensure accurate and timely procurement. Therefore, an environment in which the product information is transmitted to the system in real time through sensing technologies and the collected data can be linked with an appropriate component is required.