Shulou(Shulou.com)06/02 Report--

Some continuous production enterprises with a high degree of automation have reached the level of integration of management and control and realized paperless production, while discrete production enterprises are limited by the complexity of management and the level of technology and automation. there is a big gap between paperless production.

With the improvement of digital design and manufacturing level, it is possible to realize paperless process in discrete workshop. This trend of paperless production also makes the MES system change. The editor will give you an introduction to the paperless MES system software in discrete workshop.

Paperless MES system

Paperless production is a new production mode, continuous production mainly depends on automated assembly line, while discrete production mainly depends on workers, which requires workers to work smoothly in a paperless environment, which is much more difficult. In this mode, it is necessary to change the role of workers in workshop production: workers are the only subjects of value-added activities (that is, production) in the workshop, which is similar to hospital surgeons; the result of value-added maximization is that most production managers are gradually transformed into production support personnel, which is similar to hospital nurses.

Paperless production not only eliminates "paper", but more importantly, it forms a new production mode (the change of role and working mode). Foreign paperless workers said that "let workers twist more wrenches and record less data" is a very vivid expression of the changes brought about by paperless production.

Paperless production is changing the concept of MES system

It is generally believed that MES system is a workshop-oriented management information system located between the upper planning management system and the underlying industrial control. It provides operators and managers with information about the implementation and tracking of the plan and the current status of all resources (people, equipment, materials, customer requirements, etc.).

Manufacturing activities exist at the intersection of value chain and life cycle chain, in which the former is the requirement of traditional MES system software and the latter is the new requirement of paperless MES system software. Considering that there can be only one executive management system in the same manufacturing site, the existing concept of MES system is bound to be expanded.

The information integration of MES system is decisive for the information integration of enterprises. "paper" is the most traditional medium of information exchange, and it is also the main way to exchange information among isolated island information systems, so it can be considered that paperless MES system software not only means the fundamental change of production mode, but also embodies the highest level of enterprise information system integration.

Functional framework

This paper puts forward the functional framework of paperless MES system, and divides the paperless MES system software into nine parts: workshop plan management, production preparation management, workers'on-site job management, equipment operation management, quality operation management, visual Kanban management, man-hour management, production resume management and exception management.

From the design point of view, the functional framework of the paperless MES system software makes the following considerations:

(1) highlight the status of workers' gateway.

The worker portal can not only display visual craftsmanship, but more importantly, it enables workers to get all the information they need on the portal to prevent workers from logging into different systems to find information. The workers' portal enables information to be automatically pushed to workers, so that workers can work and record quickly, thus bringing about a new production mode in a paperless production environment.

(2) the requirement of the integration of PDM and CAPP is put forward.

In the paperless production mode, the electronic work instruction (EWI) used by workers on the workers' portal is a package of work instructions, process procedures, drawings and models (the concept of EWI was put forward by ISA95), which greatly promotes the integration of PDM and CAPP. When the integration of PDM and CAPP is not mature, the integration of MES and CAPP has also become a transitional choice. For example, Visiprise includes the module of CAPP in the MES system implemented by Lockheed Martin.

(3) it improves the efficiency of field data collection and expands the amount of information of field data collection.

MES system not only plays the role of reporting start and completion on site, but also needs to record all kinds of related information of manufacturing process according to the requirements of EWI: manufacturing environment and its related parameters, running status of tools and equipment, source and quality information of raw material blank, batch and quality information of loading parts, inspection result data, and processing information of non-conforming products, so as to obtain complete production process resume.

(4) the on-site exception management, especially in the field of technology, is particularly prominent.

In order to improve production efficiency, process transcendence and temporary processes are often completed by technicians directly at the production site. After paperless, these information need to be edited, modified and version managed in the MES system, and can correspond to the process data of PDM/CAPP. In the implementation of the project, for some discrete workshops that use unstructured CAPP, we can even emulate the practice of SAP/Visiprise and temporarily incorporate the process planning function of traditional CAPP into the MES system software.

(5) highlight the status of production preparation.

Production preparation is divided into two levels: enterprise-level distribution and field-level distribution, in which MES system is responsible for the latter. Field-level distribution emphasizes medium-and short-cycle production preparation, and strives to achieve JIT-style distribution effect, so that workers can fully adapt to the role of "surgeon" in paperless production and devote more energy directly to the production process.

(6) more emphasis is placed on the integration of various production factors and business activities.

Under the paperless production environment, the work between people becomes closer, and all the information needed for on-site production can only be managed in the computer, which greatly improves the requirements of information integration.

Specific functions of each part

(1) Workshop planning management: receive the workshop order issued by ERP, decompose it into process operation plan, and assign the job task to the site. This is the function that the traditional MES system software should have.

(2) production preparation management: manage tooling tools, workshop secondary inventory and WIP, and distribute these production resources to the site according to the requirements of process operation plan and dispatching workers.

(3) Workers'on-site operation management: carry out on-site operations around the workers' portal, workers receive work instructions on the workers' portal, report the completion of the process, and fill in the processing and inspection records. From the application of paperless production abroad, workers' portals and electronic work instructions are the key factors for discrete workshops to realize paperless MES system software.

(4) equipment operation management: manage equipment repair and maintenance process, fully record equipment operation status, grasp equipment availability to support production scheduling.

(5) quality operation management: manage the on-site inspection process, the collection of inspection data, and the handling process of nonconforming products.

(6) Visual Kanban management: all kinds of large screen Kanban used in production site, and provide visual query function for management.

(7) man-hour management: manage fixed man-hours and workers' actual processing hours, as well as the automatic generation of man-hour reports. Among them, the collection of man-hour data is completed by the field operation module, and the confirmation of man-hour data is completed by the quality operation module.

(8) production resume management: with the support of the above modules, a complete resume of the "man-machine material method ring" in the processing process is formed.

(9) exception management: deal with all kinds of exception events and their impact on production planning, and improve the adaptability and handling capacity of the system to production exception events.

The implementation of paperless MES system is not only the implementation of a software system, but also needs to include the improvement of the level of technology and hardware as the basis. Sometimes a new product model represents a new design and manufacturing mode. Therefore, the construction of paperless MES system needs to consider the problems of different product models and different application stages.

There are generally mixed production lines of multiple types of products in the workshop, so it is an inevitable choice to use the same set of MES system to adapt to the data of different maturity, especially the work portal used in the field needs to receive work instructions from different products. Therefore, in the design of paperless MES system, special emphasis should be placed on the standardization of workers' portals and work instructions to improve the functional flexibility and configurability of workers' portals.

Key technology analysis

The implementation of paperless MES system requires not only the change of management mode, but also many software and hardware technologies.

(1) production site terminal technology.

The production site terminal is used to display work instructions and work instructions, and the operator can view the work tasks, report the start and completion of the work on the terminal; if the conditions are available, they can also view the drawings, process procedures and digital models on the terminal.

Related applications abroad have shown that the use of portable wireless terminals or offline terminals is becoming an important direction of MES system applications. Especially the terminal technology which meets the security requirements of aviation military production and has the function of wireless encrypted transmission will become the key technology of aviation MES system.

The number of on-site terminals in the paperless workshop should be able to meet the needs of paperless production, in principle, a device or an operator should configure a terminal.

(2) Logistics identification technology.

MES system emphasizes the control of logistics, accurate and fast logistics management often requires the use of identification technology, including: bar code, RFID and so on. The application of logistics identification technology is more urgent in the case of paperless.

At present, miniaturized laser marking QR code, anti-metal interference and corrosion gluable RFID are all marking technologies that can meet the needs of discrete manufacturing, and the relevant national military standards are also under pre-research.

(3) automatic data acquisition technology.

The MES systems of continuous manufacturing enterprises generally emphasize the application effect of management and control integration. Due to the lack of sufficient automation integration means, the MES systems of discrete manufacturing enterprises are often difficult to achieve the degree of management and control integration, but management and control integration is always the development direction of MES system of discrete manufacturing enterprises, and it is also the inevitable direction of the development of paperless MES system. In order to realize the integration of management and control, the most important thing for discrete manufacturing enterprises is to be supported by automatic data acquisition technology.

At present, the more feasible automatic data acquisition technologies include: automatic data acquisition technology of numerical control equipment, automatic data acquisition technology of furnace temperature control system, automatic data acquisition technology of measurement system and so on.

(4) Human-computer interaction technology.

The MES system manages the execution process of manufacturing, which is full of changes and exceptions, especially when paper is lost as a record carrier. This is why human-computer interaction technology is very important for paperless MES system software.

Human-computer interaction technology generally needs logistics identification technology and automatic data acquisition technology (especially automatic test data acquisition) as the support, which can prompt the zero components that select the wrong batch serial number, verify and alarm the technical status of BOM and process supplementary files, and automatically package and analyze the measurement results. There have been engineering applications of human-computer interaction in foreign electronic assembly MES systems.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.