Abstract: Based on the analysis of the reconfigurability theory of Manufacturing Execution Systems (MES), and combined with the characteristics of ship hull section assembly lines, this paper explores the application of MES reconfigurability in hull section assembly lines from three aspects: organizational structure, workshop manufacturing resources, and production process, leveraging the advantages of segmented ship hull manufacturing operations. Keywords: Manufacturing Execution System; Reconfigurability; Hull Section; Assembly Line; Ship Section 1 Introduction Manufacturing Execution System (hereinafter referred to as MES) is an information system oriented towards the execution layer of manufacturing enterprises, providing comprehensive management of this layer. In the enterprise integrated information management system, MES plays a bridging role, helping manufacturing enterprises solve the problem of weak connection between ERP planning and production site information; it can play a scheduling and coordination role when the execution of production process plans and the control of the production site lack optimization; and it can solve problems such as difficulty in assessing enterprise production capacity and difficulty in controlling production costs. The shipbuilding industry is a complex and cumbersome manufacturing industry, facing certain difficulties in achieving automation and informatization. In order to strengthen the information management of shipbuilding enterprises, it is necessary to introduce certain information systems in a timely manner. Manufacturing execution systems enable the enterprise management information system to be integrated and operated in a timely, fast and effective manner, thereby improving the overall management level of the enterprise. Research on the reconstruction of the planar segmented production line based on MES is carried out to make the ship planar segmented production line more adaptable to the requirements of the information system and to better play the role of MES in shipbuilding [1]. 2 Analysis of MES Reconstruction Elements The purpose of realizing the reconstructibility of MES is to provide excellent services to enterprises at low cost and continuously improve the manufacturing agility of enterprises. On the one hand, developers can quickly meet the application needs of customers by adopting existing development results; on the other hand, enterprises can continuously utilize existing MES investments to optimize and expand existing systems, so that the MES system can continuously, efficiently and superiorly serve enterprises. Changes in enterprise business processes, business objectives and workshop environment are always the driving force for implementing MES reconstruction. In the process of implementing MES reconstruction, the three major elements of organizational structure, workshop manufacturing resources and workshop production process are involved to varying degrees [2-3]. The reconstruction of organizational structure mainly refers to adjusting or streamlining the various production functional departments in the workshop and reconstructing the original workshop organizational structure. The restructuring of workshop manufacturing resources is a dynamic change in workshop resources. Specifically, it is manifested in the addition or reduction of equipment, tools, and personnel, the enhancement of equipment manufacturing capabilities, the addition of quality tracking information, and the addition or removal of integration with external systems. The restructuring of the production process is necessary for enterprises to adapt to changes in business objectives and workshop environment. The workshop manufacturing system MES must be restructured. At the same time, learning and knowledge management functions are added during the restructuring process to optimize the process itself. Only when necessary can the process be restructured to adapt to changes in the environment. 3 Overview of planar segmented assembly line The hull structure is mainly composed of steel structures made of various profiles and steel materials. The hull of a ship is generally assembly line type, with only the midship section tending to be flat. In modern shipbuilding, all structures of a ship are generally divided into several blocks, called sections. Individual sections are combined into general sections or ring sections, and then combined again to finally form the entire hull structure. The most basic intermediate product unit in ship structure manufacturing is the section[3]. Based on the internal structural characteristics of the sections, they are divided into curved sections (Figure 1) and planar sections (Figure 2). Planar sections must have at least one completely straight surface. Furthermore, the structures are primarily perpendicular to each other. The length and width dimensions of the section are significantly larger than its thickness (approximately three times or more), and the other surface of the section should also be a straight or nearly straight plane. The planar section assembly line is an indispensable and important production facility in modern shipbuilding. Its main work involves the parallel midship sections, i.e., the sections excluding the bow, stern, engine room area, and superstructure. A typical planar section assembly line consists of multiple workstations, including: panel assembly station; single-sided welding station; single-sided welding repair and inspection station; longitudinal girder assembly station; longitudinal girder welding station; buffer and transverse movement station; longitudinal girder rib assembly station; longitudinal girder rib welding T-position; and inspection and transport station. The entire planar segmented production line lacks flexibility, significantly impacting the overall production rhythm when facing different scales and structures of segments, which is detrimental to information management. By modifying the workshop's organizational structure, manufacturing resources, and processes, the planar segmented production line can better adapt to segments of different scales, improving its utilization rate. 4. Research on the Reconfigurability of Planar Segmented Production Line Workshop Based on the technological flow and characteristics of the planar segmented production line, and combined with MES reconfiguration technology, this study investigates its application in shipbuilding planar segmented production lines. Referring to the three aspects of MES reconfigurability—organizational restructuring, workshop manufacturing resource restructuring, and production process restructuring—the reconfiguration of the planar segmented production line is analyzed separately. 4.1 Organizational Reconfiguration of Planar Segmented Production Line Workshop Applying MES to shipbuilding workshops requires real-time data collection and entry to facilitate users access to the latest production information. However, complex management layers are time-consuming and hinder accurate and timely information response. To achieve information-based and scientific workshop management, management layers must be streamlined. Restructuring the management hierarchy of a planar segmented assembly line workshop by reorganizing the organizational structure is optimally done by dividing the workstation as the basic unit, establishing a workstation leader, and having the workstation leader directly communicate with the workshop director. The workshop director manages the production information of the entire workshop and ensures that each workstation leader is aware of the production status of other workstations in a timely manner, so as to grasp the overall production rhythm and ensure smooth production of the entire assembly line, avoiding problems such as production incoordination between workstations, such as waiting for work. In the management system, this is reflected in the timely display of construction site data, through computer-controlled data integration and dissemination, reducing intermediate links, simplifying system users, and implementing changes to system users and user permissions within the MES system. 4.2 Restructuring of Workshop Manufacturing Resources The workshop resources of a ship planar segmented assembly line include physical resources such as personnel, equipment, and tools, as well as various information resources in the manufacturing process, such as order plans, process drawings, and inventory information. In a planar segmented assembly line, personnel have the greatest impact on the production rhythm. Just as preparation time is longer than welding time in welding, the focus of restructuring is on personnel restructuring. In actual production on a planar segmented assembly line, because workers can move to the previous workstation to start work ahead of time or continue their work at the next workstation, the production cycle of the assembly line actually has a margin of safety. At this time, workers are allowed to work outside their workstations, and each workstation can form a workpiece queue. Thus, the planar segmented assembly line can avoid waiting times or congestion. Due to these production characteristics of the planar assembly line, within the workshop, the MES system can scientifically, rationally, and flexibly allocate and arrange personnel at workstations, and restructure workshop personnel based on real-time production information, which has a significant effect on improving personnel utilization and production efficiency. For example, if all workstations from the lateral movement station to the transport station are operated manually, workers here can be flexibly transferred to other areas. That is, when encountering a large workload of three-dimensional segment construction, necessary workers can be added at any time to ensure the production cycle. When encountering a smaller workload of three-dimensional segment construction, workers can be deployed to other workstations at any time to match the production cycle of the assembly line. 4.3 Restructuring of Planar Sectional Assembly Line Production Process Shipbuilding is a typical single-piece production industry. It cannot be fully automated assembly line production according to strict standards like automobile production. Therefore, personnel have a great influence on the process [3]. The existing process of the ship planar sectional assembly line workshop is: panel assembly station - single-sided welding station - single-sided welding repair and inspection station - longitudinal skeleton assembly station - longitudinal skeleton welding station - buffer and transverse movement station - longitudinal girder rib assembly station - longitudinal girder rib welding station - inspection and transport station. Production process reconstruction is to organically organize various functional production activities in the workshop to complete the production and manufacturing process. Each functional production activity involves the corresponding workshop manufacturing resources. In order to make full use of the planar sectional assembly line, the work order in the process can be flexibly changed according to the different products being manufactured, and the working hours required for each work station, equipment changes, personnel increases and decreases, etc., to adapt to the needs of different product production. This is a great improvement for the planar sectional assembly line. The structure of a planar segment is relatively simple, consisting of multiple longitudinal and transverse stiffeners mounted on a base plate composed of multiple steel plates. Therefore, for planar segments, the workflow can be modified based on the operating time and time data of each relevant workstation. This allows for adjustments to the process to suit the different requirements of the production line for different segments. In actual production, not every planar segment needs to pass through all workstations on the planar segment production line. Planar segments are broadly divided into double-layer segments and single-layer segments. Double-layer segments pass through all workstations before leaving the workshop at the exit station; these are called three-dimensional segments. Single-layer segments leave the workshop after reaching the transverse movement station; these are called planar segments. For all segments, the planar segments need to pass through all workstations between the assembly station and the transverse movement station. At these workstations, the longitudinal and transverse stiffener splicing is separated from the main production line into a smaller, parallel line. After the longitudinal and transverse stiffeners are assembled, they are fed back into the main production line for the next step. This parallel arrangement increases the flexibility of the production line and reduces waiting times caused by the assembly of longitudinal and transverse stiffeners. It achieves the goal of saving time and improving efficiency, and can also flexibly control the operation according to different segments. 5 Conclusion The most direct benefit of the implementation of the MES system to shipbuilding enterprises is to improve the speed of production plan issuance and production result feedback, enhance the enterprise planning level's control over workshop production, and at the same time increase the workshop's real-time on-site scheduling capability, reducing the reliance on personal experience in the production scheduling process. The application of the MES system in shipbuilding enterprises requires the support of certain reconstruction technologies. The first is the reconstruction of workshop production information, so as to adapt to the needs of the manufacturing execution system, and smoothly apply it in the ship section assembly line workshop, providing a simple reference for the informatization of shipyard workshop management. In the near future, we may see MES play a significant role in actual ship production workshops. 6 Main References 1 Qiao Jianmei, Lin Yuan, Wang Haizhen. Discrete manufacturing industry moves from ERP to MES. Mechanical Management and Development, 2006, (2): 104 2 Yu Daoyuan, Peng Ning, Huang Gang. Research on reconfigurable MES architecture. Modern Manufacturing Engineering, 2007, (4): 20 3 Overview of Manufacturing Execution System (MES). China Manufacturing Information Portal. www. e-works.net.cn 4 MESA. MES Functionalities 8L MRP TO MES Data File Possibilities. MESA International— white paper No. 2. 1997. 5 Ouyang Beijing, Li Weijia. Research on Automatic Assembly Production Line for Ship Hull Planar Sections. Guangzhou Shipyard Science and Technology, 2001, (3): 29 6 MESA. ES Explained: A High Level Vision. MESA International— white paper No. 6, 1997.