Abstract: This paper introduces the main functions of a Manufacturing Execution System (MES), and designs and applies a MES based on its principles. According to the requirements of cost management data collection, the system completes the collection of cost data, ultimately realizing workshop cost management. Keywords: MES, Cost Data Collection 1. Introduction In today's society, enterprise competition is fierce, and only the fittest survive. Strengthening cost management is an effective way to improve the competitiveness of enterprise products. Cost accounting is an important part of enterprise accounting work, and accurate cost information is an important basis for enterprise decision-making. Enterprises mostly rely on the application of computerized accounting software to solve cost management problems. However, because current computerized accounting software cannot automatically collect cost data, manual methods are still needed to establish cost data. Therefore, from the perspective of cost management, current computerized accounting software merely plays the role of manual bookkeeping "with the help of computers." The cost accounting methods and management mechanisms remain the same as before, and its role is inevitably insignificant. For the manufacturing industry, enterprise costs mainly occur in the production process, and the production workshop is responsible for production tasks. Therefore, workshop production cost management is inevitably a key focus of cost management, and it is an important source of cost data collection for enterprises or computerized accounting software. 2. Manufacturing Execution Systems Many companies use theories such as ERP (Enterprise Resource Planning) and JIT (Just-In-Time) to provide effective solutions and tools for production management. However, because shop floor production management emphasizes the execution of production plans and the collection and feedback of production data, while ERP and JIT emphasize corporate planning, they fall short in shop floor production management and control. This problem was not fully solved until the emergence of the theory of "Manufacturing Execution Systems." In the 1990s, the Advanced Manufacturing Research (AMR) in the United States proposed the concept of "Manufacturing Execution Systems" (MES) and positioned MES to focus on solving shop floor production management problems. AMR defines MES as "a shop floor-oriented management information system located between the upper-level planning and management system and the lower-level industrial control system." It provides operators/managers with information on plan execution, tracking, and the current status of all resources (people, equipment, materials, customer needs, etc.). MES plays a crucial role in enterprise information systems. Under the guidance of the production plan generated by the ERP system, it collects real-time data related to production from the underlying control system, arranges short-term production operations, monitors, allocates resources, and optimizes the production process. The functions of MES are shown in Figure 1, which also shows the integration relationship between MES and other application systems. (1) Resource allocation and status management: Manages resource status and allocation information, including machine tools, auxiliary tools (such as cutting tools, fixtures, measuring tools, etc.), materials, workers and other production capacity entities, as well as documents (process documents, CNC machining programs of CNC equipment, etc.) and detailed historical data of resources that must be available when processing begins. Resource management also includes the reservation and scheduling of resources to meet the requirements of the production plan. (2) Process-level detailed production plan: Responsible for generating process-level operation plans, i.e. detailed plans, and providing job sequencing functions based on priority, attributes, characteristics, methods, etc. related to specified production units. Its purpose is to arrange a reasonable sequence to minimize auxiliary time in the production process. (3) Production scheduling management: manages and controls the flow of materials and information in the production unit in the form of operations, orders, batches and work orders. Production scheduling can adjust the production operation plan specified by the workshop, handle rework and scrap, and control the quantity of work-in-process at each point using buffer management methods. (4) Document management: manages records/documents related to the production unit, including drawings, formulas, process documents, engineering changes, etc. This part also completes operations including maintaining the stored production history data. (5) Field data acquisition: responsible for collecting various necessary real-time updated data information in the production field. This field data can be manually entered from the workshop or obtained by various automatic methods. (6) Human resource management: provides real-time updated employee status information data. Human resource management can interact with the equipment resource management module to determine the final optimized allocation. (7) Production quality management: analyzes the data collected from the manufacturing field in real time to control product quality and identify problems that need attention in production. (8) Production process management: monitors the production process, automatically corrects errors in production, improves processing efficiency and quality, and provides users with decision support for correcting errors and improving work-in-process production behavior. (9) Production Equipment Maintenance Management: Tracks and guides enterprises in maintaining equipment and tools to ensure the smooth operation of the manufacturing process, and generates phased, periodic and preventative maintenance plans in addition to alarms, and also provides responses to problems that directly require maintenance. (10) Product Tracking and Product Data Management: Obtains the historical records of each product by monitoring the position and process status of the workpiece at any time. These records provide users with traceability of the product group and the usage of each final product. (11) Performance Analysis: Provides real-time updated results reports of the actual manufacturing process and compares these results with past historical records and expected business objectives. 3. Cost Data Acquisition Methods in MES Current workshop cost accounting is mostly manual, resulting in slow cost information extraction, low accuracy, and difficulty in achieving cost control. Existing MRPII or computerized accounting software are all upper-level management systems of enterprises, and their cost accounting is also a first-level accounting of the enterprise. Some domestic enterprises have developed software to calculate workshop costs separately based on specific workshop accounting methods. However, the collection of cost data is still done manually, making it difficult to manage workshop production costs. An important function of the Manufacturing Execution System (MES) is to collect various necessary real-time updated data information from the production site. It has a set of mechanisms and methods to collect production site data. Therefore, according to the requirements of cost management, some data collection items for workshop cost management can be specifically designed in the NES system, such as the types and quantities of raw materials consumed. 3.1 Content of Workshop Cost Management Workshop cost management includes cost accounting, cost analysis, cost decision-making, and cost planning. Workshop costs are derived from various expenses incurred in workshop production and mainly include the following expense items: (1) direct materials; (2) direct labor; (3) manufacturing overhead. Workshop cost management mainly involves supervising and controlling the occurrence of workshop expenses, providing decision-making basis for workshop management, and rationally arranging production personnel and non-production personnel to achieve real-time control of production costs and provide timely and accurate data for enterprise cost accounting. 3.2 Cost Data Collection Items in MES According to the above analysis, for workshop cost management alone, the data items that MES needs to design and collect include: (1) Information on operators of each process for various parts, including the names of all operators who complete the process, operation time, etc.; (2) Information on equipment that undertakes the production task of the process, including the names of all equipment that complete the process, operation time of the equipment, etc.; (3) Types and quantities of raw materials used in the process; (4) Data collection on various manufacturing costs of the vehicle. Designing corresponding cost data collection items in MES can directly generate financial data from production activities, directly convert the physical material flow into the value form of capital flow, and unify the current location, quantity, status and value of the materials required for production, realizing the integration and unification of logistics and capital flow, and ensuring consistency between production and financial data. The finance department can obtain capital information in a timely manner and apply it to cost control, reflect the logistics and production operation status through the capital flow status, analyze the economic benefits of the enterprise at any time, and participate in decision-making, guidance and control of production and operation activities. 4. Application Example Based on the above ideas and methods for MES-based driver cost data collection and aggregation, this paper designs a workshop MES management system for a large locomotive manufacturing plant, and adds a workshop cost management subsystem to the MES system. The relationship between the MES system and other enterprise application systems is shown in Figure 2. [align=center] Figure 2 Relationship between MES system and other enterprise application systems[/align] ERP transmits information such as workshop production plans, BOM/drawings/process documents, and enterprise production resources to the MES. In the MES (Manufacturing Execution System), workshop operation planning management generates section production plans based on the workshop production plan; section operation management includes the preparation of daily production plans for sections, the issuance of daily production tasks to equipment and operators, the management of work order collection (cost information collection), and the statistics of daily production progress; workshop material management establishes material ledgers, records, queries, and maintains inventory materials, and maintains and manages material receipt and dispatch logs; workshop labor and personnel management performs time calculation, quota calculation, indicator calculation, and plan calculation; performs employee production capacity balancing calculation, individual quota statistics, team quota statistics, and unit product actual consumption statistics; summarizes employee attendance statistics based on attendance; calculates team and individual bonuses and wages based on team and individual scores; workshop quality management manages production quality data, completes the management of workshop team comprehensive management assessment information, quality information management data, and quality inspection data; key process quality data analysis maintains and analyzes the inspection data of key processes and key items. Scrap information is transmitted to workshop cost management, workshop labor and personnel management, and workshop material management systems. The product data management module primarily manages product structure data (Bill of Materials, BOM), product processing technology data, and other basic data required for workshop production. Workshop cost management aggregates and statistically analyzes the product cost information collected by the aforementioned subsystems to form workshop cost accounting, and then transmits this information to the enterprise's financial software system for cost accounting and management. This application model demonstrates that the collection and aggregation of the enterprise's cost information is completely synchronized with the product's production process, ensuring the accuracy of the data. 5. Conclusion This paper, guided by Manufacturing Execution System (MES) theory, studies a method for combining workshop cost management with advanced production management models. This makes MES an important means of collecting cost information and data for enterprises and production workshops, inevitably improving the accuracy of enterprise cost accounting.