Planning and implementation of CAPP in enterprise

The 21st century is a period of vigorous development of enterprise information construction. Due to the rapid development of modern computing technology, communication technology and microelectronics technology, computer-aided technology has also been widely and deeply applied in manufacturing enterprises. With the deepening of market economy, in order to adapt to market changes and improve the competitiveness of enterprises, we must strive to shorten the preparation cycle of process technology and improve the quality of process design and the ability of process rapid response. An important means to improve the quality of process design and the ability of rapid reaction is to comprehensively apply CAPP technology and take the development path of process informatization

capp is the abbreviation of computer aided process planning. It is a process information work platform that uses product data management (PDM) as the data source for process design and management, and provides basic data for product manufacturing, cost management and other management systems. Therefore, when we plan and implement the CAPP system, we not only require to solve the problem of process design and management, but also require it to solve the problem of data integration with other data management systems. It is technically and economically feasible to convert low-density plastic film into fuel and other recycled products in a large range, which is the key link to realize information integration in product design and production management

2 application background

for a long time, our informatization foundation is relatively weak, and product design and process mostly rely on manual completion. Product designers and process designers basically rely on paper documents to transmit information. Process design data cannot be directly used by product design data, and the information between process personnel cannot be well shared, resulting in a great waste of resources. With the continuous improvement of the company's products and the continuous change of the market, the original working method can no longer meet the needs of the company's rapid product response

by the beginning of this century, we have also used CAD, word, Excel, WPS, V Fox and other software to design a large number of process procedures, accumulated some data foundation, and basically realized the requirements of "drawing board" in process design and tooling design. However, such process documents have different formats, scattered distribution, and most of them exist in the form of text documents, so the company cannot effectively manage and utilize process data. In recent years, with the continuous development of information technology and the gradual improvement of the company's intranet, the application of computer technology in the company has been popularized to a large extent, creating conditions for the full application of CAPP technology and the realization of informatization of the whole company at present

3 function planning of the system

process design has a wide range of work, numerous data and complex management process. Process data plays an important role as a basic data source in the whole production management system, and for a manufacturing enterprise, it often has diversity (different types of work have their unique data from the traditional architectural aluminum profile format) and dispersion (distributed in multiple different processing units). In view of the company's process characteristics of multiple varieties and small batches, we abandoned the so-called derivative and generative systems that blindly pursue "process design automation" and are difficult to implement and have a very low success rate, and adopted the current general hybrid CAPP system based on case and process knowledge. After extensive research and comparison, we cooperated with Tsinghua Tianhe company, which represents one of the mainstream development directions of CAPP in China. Adhering to the road of "I-centered and joint development", from the perspective of information integration of the whole company, according to its own process work characteristics and software characteristics, the company's CAPP system requirements were carefully analyzed, comprehensively considering the company's management mode and process characteristics, and jointly formulated and successfully implemented with the software company the CAPP planning scheme of our company. According to our process design management principles, in addition to considering the practicality and popularity of the system, we focus on the following key functions of CAPP system when planning:

3.1 data integration

CAPP system does not exist in isolation. Generally speaking, before formal process design, it must first obtain relevant product data from external systems, so as to provide basic process information for process design; In addition, the process data processed by CAPP is required to be transferred to other management systems as the basic data for the production management system to make decisions. Therefore, the system should have the ability to easily obtain data from the outside and process and export internal data

3.2 product process management

our products are characterized by many varieties, high degree of serialization, mutual borrowing of parts and components, and high repetition frequency. In order to avoid multiple maintenance of the same process information in the system, the system is required to ensure the uniqueness of each node and process document while ensuring the integrity of product structure

3.3 data format and process card

our company has a wide range of processes, including machining, electroplating, heat treatment, casting, powder metallurgy, cold work, paint and other process data. Various process data have different data requirements according to their professional characteristics. Moreover, the expression forms of different process data (process card) are diverse. It is not only the input window of process data for process personnel, but also the print window to realize the paper transmission and archiving of process documents. Therefore, the system must have the ability to customize the data format and process card according to the specific process requirements of the company

3.4 permission system

in our company, there are many departments and personnel related to process, and different departments, majors and personnel have different operating permissions for the system. Therefore, the system must ensure the security of data operation in the collaborative work environment, and can control the corresponding operations and access permissions of different personnel according to the actual situation of the company

3.5 resource utilization

in the long-term process work, we have accumulated some process design resources, including process terminology, process rules, process specifications, process design manuals, equipment, tooling and so on. In process design, we often need to query or call the existing relevant resources of the company to improve the efficiency of process design and process standardization, and share information with other systems. Therefore, we require that relevant resources can be easily queried and called in real time in the system

4 system architecture

according to the above overall scheme, we worked with the software company to carry out secondary development on the basic functions provided by the software according to the overall requirements of the company's informatization, and built a networking process platform based on large database (Oracle) with company characteristics. In this system, process related personnel log in and enter the work interface according to their respective authority passwords, and carry out operations such as PDM data integration, browsing PDM drawings, process design, process browsing, process flow review, printing, etc. according to the operation authority assigned by the system. The process design revolves around the product structure tree and is clear. The process card realizes the complete "what you see and what you get" function, which is popular and practical. In the process of process preparation, the system can query or call various process resources defined by the company at any time, and can intelligently screen according to the content of process preparation. It has formed a set of process design system with certain intelligence that organically combines data and data, people and data, management and data, and management and people, and meets the rapid interaction based on knowledge accumulation (see Figure 1)

5 data integration mode

as an auxiliary process planning platform, CAPP should not only realize the effective management of internal data, but also exchange information with other data management systems. Therefore, in addition to its internal components, plug-ins and specialized modules, white et al. Reported the animal experiment of penetrating artificial cornea with Proplast. The artificial cornea was stable after surgery, and fibrous cells grew in the initial stage. The case with the longest survival time was more than 3 years. It was highly integrated. At the same time, it also required data integration with other data management systems outside the system (see Figure 2)

5.1 upstream data

the basis of data integration is Bill of materials (BOM). The engineering bill of material (EBOM) and the planned bill of material (pbom) are created in our PDM. The engineering bill of material reflects the assembly relationship from parts, assemblies, components and assemblies to products in turn. The planned BOM further reflects the manufacturing source relationship from raw materials to blanks and then to parts. The engineering bill of materials and the planned bill of materials adopt one-way linkage technology (that is, the change of EBOM will be reflected in pbom, but the change of pbom will not affect the change of EBOM in turn), which ensures the accuracy of the engineering bill of materials, which is the data source of the product

5.2 integration with upstream data

planned BOM pbom is the basic data for the integration of other data management systems (such as CAPP, MRP Ⅱ, ERP, etc.). On the working interface of CAPP, you can directly enter the PDM system to integrate any level of product information, thus forming a product structure tree corresponding to pbom in CAPP. In CAPP, the system ensures the structural integrity of each self-made product tree, but also ensures the uniqueness of each node

5.3 data transmission with other downstream systems

all process data generated by CAPP is one of the important basic data sources of enterprise informatization and the main basis for guiding enterprise production and operation activities. According to the requirements of ERP for process data, we have carried out the secondary development of process data collection. Through the data processing module of CAPP, we can directly access the bottom process database of CAPP, and automatically process the rules according to the process data format required by the company, and then directly import them into the data base of relevant systems (sql-server or Oracle, etc.), so as to realize the data exchange with other data management systems (such as MIS, MRP Ⅱ, ERP)