Research and Application of MES for the Automobile Mould Industry

With the increasingly fierce competition in the manufacturing industry, many companies have implemented the MRPⅡ/ERP system to strengthen production governance. However, due to the lack of sufficient workshop control information, they cannot meet the random and dynamic requirements of the company’s production and cannot meet the workshop environment. They are closely connected, so they cannot effectively guide the execution of the workshop’s production plan. With the continuous promotion of enterprise informatization applications, the level of enterprise informatization applications has gradually improved, and enterprises increasingly need management information systems at the executive level of the workshop.

At present, most auto mold companies mainly rely on manual management for their workshop production. The planning layer and the control layer are disconnected from each other and cannot adapt to the dynamic changes of the production process, which greatly restricts the further progress of the production management level. The emergence of Manufacturing Execution System (MES) has filled the vacancy of workshop-level governance. MES takes job scheduling as its core and aims to reduce production costs and improve production efficiency. It collects real-time information in the production process and processes real-time potential parts in a timely manner. At the same time, it maintains two-way communication capabilities with the planning layer and the control layer. The layer receives relevant information and feeds back processing results and production instructions, thus realizing the optimization of the entire production process. This article proposes the construction and application of MES for automobile molds based on the production characteristics of the automobile mold industry and the status quo of information management.

The production characteristics of automobile molds and the status quo of information application

2.1 Characteristics of automobile mold production

As an important process equipment of the automotive industry, molds are the process foundation of the automotive manufacturing industry. Due to the complexity of the product itself and its typical single-piece order production method, its production is different from ordinary products. The characteristics are as follows:

• (1) Order-oriented production. Due to the large changes in order specifications, numbers, and delivery dates, each product has its particularity. From product order decision to manufacturing, each set of molds has a certain degree of independence, and companies must organize production according to the order.
• (2) The production schedule is difficult to control. Since the product is produced in a single piece, almost every product needs to be redesigned, crafted, and technically prepared. Therefore, it is often impossible to grasp the changes in the production schedule in time, and it is difficult to control the entire production process.
• (3) Changes in plans. Due to the wide variety of products, there are many uncertain factors that affect the production process. There are often emergency orders, equipment failures, and parts rework and repair, which make the plan changeable, and even the plan cannot keep up with the changes and is out of touch with the actual production.
• (4) Difficulties in production governance. The mold manufacturing process is complex, and there are many uncertain factors in the production process. The coordination of the entire production process cannot be guaranteed by empirical scheduling, process control is difficult, and governance is difficult.

2.2 Current status of informatization application in the automotive mold industry

At present, the informatization construction of my country’s automobile mold industry has just started, and the development level of networking and informatization is still relatively low. After specific investigations, it is found that the following problems mainly exist:

• (1) Workshop governance mainly relies on manual work, and it is impossible to effectively manage the massive data in the production process. It is difficult to ensure the correctness and consistency of information required for various production activities, and it is difficult to respond to dynamic changes in production in a timely and rapid manner.
• (2) Most automobile mold companies have a low degree of networking, and the phenomenon of “information islands” is prominent. Data of various parts cannot be shared in real time, which affects the consistency and correctness of enterprise data, and seriously hinders the development efficiency of mold products.
• (3) The mold production process lacks effective monitoring, it is impossible to realize the timely feedback of manufacturing process information, it is difficult to grasp the production progress and production capacity in time, and it is difficult to effectively track the work in process.

The existence of the above problems is not conducive to the integration and sharing of information in the production process of the workshop, and seriously hinders the progress of the development of enterprise informatization, thereby affecting the further improvement of enterprise production efficiency and competitiveness.

3 MES for the automotive mold industry

3.1 Architecture

Establish an open and sensitive manufacturing execution system based on large-scale relational database technology, using object-oriented technology and soft bus technology, so as to realize the monitoring and control of production information and the optimized management of the production process.

The top-level planning layer is MRPⅡ/ERP and other systems. Its role is to manage various production resources in the enterprise, formulate factory-level production plans, etc., and is mainly responsible for the planning of corporate activities and production decisions.

The middle layer is the MES execution layer, which is mainly responsible for the execution and control of the production plan.

The production control layer includes computer control systems such as DCS (distributed control system), PLC (programmable logic controller) and DNC (distributed numerical control equipment), which are mainly used to control the production process and equipment.

MES provides a way to systematically integrate planning and scheduling, material tracking, production scheduling and other functions on the same platform. Through the integration with the planning-level governance system (ERP) and the underlying control system, planning, production and control are tightly integrated. Connect, thus establishing a communication bridge and link between the planning layer and the control layer.

3.2 Functions of each module

The MES system mainly includes main modules such as production planning and job scheduling, station electronic kanban, material tracking, production cost management, production statistics and analysis, and system management. The functions of each module are as follows:

(1) Production planning and job scheduling module

The production planning and job scheduling module is the core of the automotive mold MES. On the basis of effective integration with other modules of MES and ERP system, through limited capacity job scheduling, determine the processing sequence of all workpieces on the equipment, as well as the start and completion time of each process of equipment processing. When urgent orders, equipment failures, rework and repairs, production delays, etc. occur at the production site, reasonable optimization techniques and methods are used for production scheduling, and the operation plan and scheduling resources are adjusted to adapt to the actual production conditions, thereby improving production The continuity of the process ensures the efficient operation of production.

(2) Electronic kanban module for workstations

The electronic kanban is a visual kanban based on the computer network for the operation of the workshop. The station electronic kanban module displays the production task list and related process information on the kanban of the operating station in a timely manner through the workshop computer network, and issues production instructions to the operators, thereby realizing network dispatching and providing them with operating procedures, equipment, and tools , Materials, auxiliary materials and other work instruction information. To

(3) Material tracking module

The material tracking module uses bar code technology to track the entire mold production process, collects work-in-process activities, material consumption, product rework, repair and scrap in real time, and obtains the specific historical records of each mold, so as to make the product production process transparent and realize The traceability of each mold production process.

(4) Production cost management module

According to the dynamic operating cost method, the cost is specifically classified, collected and distributed according to different tasks, and the variable cost and the fixed cost, the controllable cost and the non-controllable cost are correctly divided, based on the processing and assembly process described in the product BOM, combined with real-time The data collection information from the low-level to the high-level is accumulated layer by layer, so as to calculate the production cost of the workshop. It reflects the actual process of product dynamic value-added, and can accurately and accurately realize the accurate statistics of cost in real time.

(5) Production statistics and analysis module

The production statistics and analysis module will realize the statistics and analysis of production planning, production execution progress, quality inspection, resource utilization and other information on the basis of effective integration with other MES modules and ERP systems, in order to better optimize the production process ,Improve product quality and maintain the best production state to provide support.

(6) System management module

Administer system users according to roles, manage their parts, positions, staff, permissions and other information, save system login records, ensure the safety and confidentiality of product information, provide system data backup and data recovery functions, and ensure the safe operation of the system.

3.3 Key technologies

MES is the focus of the informatization construction of the automotive mold industry workshop. The successful development and application of MES is related to the success or failure of the informatization construction of the automotive mold enterprise. Its key technologies mainly include:

(1) Job sequencing optimization technology

Job scheduling optimization is the core function of production planning and job scheduling, which determines the best processing sequence of workpieces on equipment or work centers. The priority scheduling rule method of heuristic algorithm is used to optimize the job order. The pre-defined priority rule is used as the heuristic condition, and the job with the highest priority is selected from the waiting jobs to schedule processing. In the processing priority setting, the delivery date, parts, and equipment are comprehensively considered, and the mold priority is set according to the delivery date; the part priority is artificially set according to the actual situation and experience; according to the scheduled The principle of least task sets equipment priority. This method is easy to implement, has low computational complexity, and the processing priority can be adjusted manually, so that the scheduled operation sequence is more in line with the actual production.

(2) Barcode data collection technology

Barcode data collection technology is a comprehensive scientific technology based on computer technology, photoelectric technology and communication technology. It is an important method and means for information identification and collection. It has fast speed, high accuracy, simple operation, and collection of information. Advantages such as large quantity. Using barcode automatic identification technology to collect and track the logistics information of the production process, it can monitor the entire production process in real time, record and process a large amount of data in production, realize data traceability, reverse check, and report functions, and improve governance efficiency and quality.

(3) System integration technology

In order to realize the sharing and exchange of product information of heterogeneous systems, XML (Extensible Markup Language) neutral files are used to realize the integration of MES and ERP systems and control systems. XML technology has the characteristics of openness and extensibility, and can exchange and share data between different programs. The integrated information of MES and ERP system includes production plan, BOM information, process information and material information. This type of integration can not only improve the accuracy and consistency of data transmitted between systems, but also improve the speed of information feedback, which is conducive to information sharing.

4 MES development trend

MES is an information management system oriented to the shop floor, and its application has brought huge economic benefits to the enterprise. With the development of information technology and the competitive needs of manufacturing companies, companies have put forward higher requirements for MES application technology. Meeting the requirements of integration, adaptability, openness and collaboration is the development trend of MES. The specific performance of the following aspects:

• (1) Using XML technology to solve the problem of data heterogeneity between MES and ERP and the underlying control system, making the system more open, integrable, and more closely integrated;
• (2) On the basis of research on MES software products of automobile molds, establish general solutions for the discrete industry to meet various specific practical needs of the discrete industry;
• (3) Governance technologies and concepts such as data mining, knowledge governance, optimization technology, and lean thinking will be widely used in MES to promote the development of MES theory;
• (4) With the development of information and network technology, collaborative MES has become a hot research topic.

5 Conclusion

Analyzing the production characteristics of automobile molds and the status quo of information applications, the system structure and functions of the manufacturing execution system centered on production planning and job scheduling are proposed, and the key technologies and future development trends of the system implementation are further elaborated. Through the construction of automobile mold MES, a production information sharing mechanism and platform have been established, the digital governance and control of production resources and production processes have been strengthened, and a communication bridge has been erected between the planning layer and the control layer to achieve production “Integration of management and control.”