How to rationally embark on the MES Application Path

In recent years, manufacturing execution system MES has received widespread attention. At the same time, mes applications also have many problems. This article describes the architecture, features, Status Quo, Problems, and relationship with ERP of MES in Discrete Manufacturing for your reference.

I. Definition and architecture of Manufacturing Execution System (MES) according to the definition of MES by American AMR research company: MES is an information system at the factory layer, between the planning system of the enterprise leadership and the direct industrial control system of the production process. It provides operators/administrators with data and information about all resources (personnel, equipment, materials, tools, and customer requirements) in the production process from the current perspective. MES plays an intermediate role in the integrated factory automation system. Guided by the long-term plan generated by the ERP system, mes collects real-time production-related data based on the underlying control system, plan, monitor, configure resources, and optimize the production process of short-term production jobs. Function modules include detailed process scheduling, resource allocation and status management, production unit allocation, process management, human resource management, maintenance management, quality management, document control, Product tracking and product list management, performance analysis and data collection modules. At the lower layer of MES, it is an underlying production control system, including DCs, PLC, NC/CNC and SCADA or a combination of these types. MES is between the ERP and the control system of the business planning system. It answers questions about how to generate. The main functions of MES in Discrete Manufacturing include: flexible Production Line FML, flexible manufacturing system FMS, flexible manufacturing unit FMC, Distributed Numerical Control DnC, automated warehouse AS/RS, Logistics and Transportation Automation and management, production preparation, job scheduling, equipment capabilities status management and monitoring, collection and feedback of production status data, quality management, and tooling inventory status. Ii. Special Manufacturing Execution System of MES in discrete manufacturing industry is an integrated system of workshop layer management and control. Compared with the process industry, mes in the discrete manufacturing industry has the following characteristics: (1) the characteristics of the discrete manufacturing industry lead to difficulties in production planning and scheduling. The production process of discrete manufacturing enterprises is intermittent. The production process varies with parts, the variety and specifications of parts are many, and the product structure is complex, making the production planning and scheduling very difficult. (2) Different Forms of workshops have different management needs. Discrete Manufacturing Enterprise workshops have different production targets, including casting workshops, forging workshops, heat treatment, machining workshops, and assembly workshops. Batch production is also different, divided into flow production workshop, multi-variety small batch production workshop. For workshops of different forms, management requirements are different. (3) The underlying automation degree varies greatly. A batch flow production workshop may consist of several production lines, such as stamping lines, welding lines, paint lines, and assembly lines in automobile production. A flexible manufacturing system (FMC), a flexible manufacturing unit (FMC), and a Distributed Numerical Control System (DNC) composed of multiple types of machining workshops may be included. A large number of workshops are composed of numerical control single-host machines and several common machine tools. Some rivet welding workshops are basically manual jobs and there is no underlying automation. Therefore, the integration of MES and the underlying control system varies widely. (4) data collection methods vary with the underlying automation. The networked system of NC machine tools can directly obtain production information and machine tool running status information from the numerical control system. The flow production line can set data collection points to collect production information; for workshops that work manually, only bar codes, RFID, and so on can be used. (5) system integration is very difficult. The MES system is closely related to the basic data, production plan, cost management, quality management, equipment management, and performance management of ERP. The difficulty of integration can be imagined. The integration of MES and the underlying control system also makes it very difficult to integrate interfaces because of the wide variety of devices. Iii. Current Situation of MES in China's discrete manufacturing industry since Shanghai Baosteel introduced the first MES system 20 years ago, MES research in China has gone through a difficult development process. From the central Government to the local government, a lot of research has been carried out in universities, research institutes, IT companies, automation companies, and enterprises, and has made gratifying achievements in metallurgy, petrochemical, tobacco, food, and other industries. However, customization and development and many laboratory products are the main problems of MES at present. The commercialization of MES applications is still a long way to go. The discrete manufacturing MES system has a big gap with the process industry in terms of software products, application breadth and application depth. There are many applications in the process industry, and only electronics and automobiles are used in the discrete manufacturing industry. Iv. Current Problems of MES in China's Discrete Manufacturing Industry at this stage, China has made some achievements in MES system research, software development, and implementation applications, however, there is still a big gap between expectations. (1) The MES system is incomplete. As mentioned above, the workshop production objects in discrete manufacturing industry are different, the production organization and production batch are different, and the requirements for MES are different. Currently, no product can cover all the workshop types, and is in the custom development stage, without mature product software. (2) Serious information islands. There are many integrated interfaces between MES and ERP systems: MRP is the source of MES system production tasks, and MRP needs to obtain in-process information of the workshop; the Cost Management of ERP should obtain in-process data and various material consumption data from the workshop; mes should share the main material data; equipment management and quality management should be related to MES. The integration between MES and CAD/CAM/CAPP/PDM of the technical information system also exists. MES and the underlying control system also have information integration problems, and the requirements for integration vary with the underlying control system. The integration relationship is complex, and the system comes from different vendors. The integration is very difficult, resulting in serious information islands. (3) Poor versatility and configurability. Due to custom development, mes systems have poor versatility, configurability, and scalability. It cannot adapt to various business needs and process changes, affecting the promotion of the system. (4) poor real-time performance of the system. The MES system for workshop manufacturing has high real-time requirements. However, due to the diversity of data sources and the lack of real-time data collection methods, the MES system has poor real-time performance. (6) poor intelligence. How to form a closed-loop control mechanism for job planning, execution, and feedback, and how to scientifically handle various interference factors that affect execution of the plan remains to be studied and improved. 5. How to correctly use mes functions MES is a technology developed after ERP. Some mes functions already exist in the ERP system, such as workshop task management, workshop operation plan, workshop statistics, workshop material management, and equipment management. These systems are closely integrated with other ERP management systems. In workshops with low equipment automation, these functions meet the MES requirements to a large extent. However, it is undeniable that the integration of MES functions in ERP with the underlying control system and information system is missing, and it still needs to be improved because it does not support various job types and data collection in workshops. In reality, some enterprises abandon these mes functions of ERP and seek an independent MES system. The functions completely overlap with the MES functions of ERP, which increases the workload of integration. There are also some manufacturing enterprises that have spent a lot of money to launch the ERP system, but for various reasons, the material demand plan MRP is not running, of course, the workshop operation plan, Workshop Material Management is also impossible to run, as a result, enterprises try to use mes to solve the problem of production planning, which is not feasible. For a manufacturing enterprise, the operation of MRP is crucial. Only by successfully running MRP can the enterprise ensure the data source of MES functions, enterprises must effectively integrate the MES control and Manufacturing Execution Systems and ERP of the enterprise resource planning system to better guide enterprises to maintain long-term development benefits, MES can become a tool for implementing the plan.