## 3 Port COBie Schema for Digital Data-Based Facility Management  
### What Is the Existing COBie? This section develops a COBie schema for port facility management. COBie stands for \"Construction Operation Building Information Exchange,\" and it is designed to operate construction facilities. In the design phase, facility management information (e.g., general facility information and spatial information) is generated [16]. This information is transferred to the facility management phase via drawings, specifications, or in the form of documents such as maintenance plans and guidelines. Most of the facility information submitted by contractors is based upon data prepared via specialized companies, manufacturers, and suppliers directly involved in building or delivering equipment or systems. However, for the facility manager to utilize these data in the facility management system, it is necessary to directly identify the data generated in the design and construction phases that are required for facility management, as well as to input these data as the initial data of the facility management system [16]. Although BIM is used to solve these problems, its utilization is limited by the excessive cost of introducing software or developing a BIM-based facility management system [17]. Therefore, an International Foundation Class (IFC)-based method to easily apply BIM data in the facility management phase is urgently required [18]; this has led to the COBie data exchange system, which was developed by governmental agencies in charge of issuing orders for major infrastructure projects in the United States [17]. COBie is a data exchange format developed by the Corps of Engineers to facilitate the utilization of BIM data in the IFC; it has been developed up to Ver. 2.4. Although Ver. 2.5 for IFC4\(\times\)3 has been released, Ver. 2.4 is more commonly used [19]. COBie is an IFC standard that supports the direct exchange of information between software and the spreadsheets used to collect necessary data [16]. As shown in Figure 1, the information required for COBie is not collected by reproducing or re-entering facility management information following the completion of construction; rather, the data generated by the participants in the representative projects of each process (e.g., the design, construction, and operation phases) are used directly, without having to wait until the end of the project. This is a process-oriented representation method in which information producers directly contribute at the time of creation; with this, it is possible to reduce the cost, procurement, and management difficulties that arise in the final post-construction phases of the project, whilst also generating and storing as-built drawings and transferring them for facility management [17]. The COBie system used in the architecture comprises 18 worksheets (\"Contact,\" \"Facility,\" \"Floor,\" \"Space,\" \"Zone,\" \"Type,\" \"Component,\" \"System,\" \"Spare,\" \"Resource,\" \"Job,\" \"Document,\" \"Attribute,\" \"Coordinate,\" \"Connection,\" \"Issue,\" \"Impact,\" and \"Assembly\") and has a structure as shown in Figure 2. Each worksheet in Figure 2 represents a type of database; these are structured to hold a variety of data, as shown in Figure 3.  
The COBie specification developed alongside COBie designates specific milestones that require data input for each phase of a project, as shown in Table 1; furthermore, it defines who should input what information.