Design method of MES for the hottest small batch m

The design method of MES for small batch machinery manufacturing enterprises

small batch and amorphous product enterprises (hereinafter referred to as small batch enterprises) can only organize production according to orders, while the user needs a variety of varieties, and often the construction period is urgent, and the enterprise has no inventory products to supply. In MES design, due to the uncertainty of products and the variability of processes, it is difficult to form the product structure database and process route database, and it is difficult to determine the business processing process. Even if the product structure database, process route database and business processing process are reluctantly designed, they do not reflect enough industry and enterprise characteristics, and do not have enough applicability, adaptability and expansibility in actual operation, It leads to poor user benefit and short system lifetime, which affects the effective development of enterprise informatization in such enterprises

due to the extremely low degree of structure in information processing, the informatization work of these small batch enterprises has remained in the state of "information island" for a long time, the informatization environment is difficult to standardize and standardize, and the information sharing is also very poor. In terms of production management, the timeliness and effectiveness of the implementation of engineering plans, production plans and construction plans are not high; The efficiency of process design is low, the repeatability is high, and the consistency and rationality of work estimation and material estimation are poor; During the quality inspection, the quality analysis and identification information is incomplete, the quality information cannot be fed back in time, and the construction operation cannot be guided in time, etc

through the induction and analysis of the production management business of small batch enterprises, and the experience of MES software development and application, this paper puts forward several basic methods for the design of this kind of enterprise information system, mainly including the product feature library that describes the product characteristics, the reference process library that records the typical product process, and the business process design method that combines breadth and strictness

first, replace the product structure library with the product feature library

no matter what type of machinery manufacturing enterprise, the engineering plan starts from the customer order to the project settlement, which constitutes the basic information throughout the production management. How to formulate a standardized engineering plan that meets certain standardization requirements, and how to maximize the use of previous production management information in the process of preparing engineering plans has become the primary problem of small batch enterprise informatization

1. Formation and use of product feature library

in the face of a customer order, no matter whether the drawings, process requirements and other technical data are complete, there are three situations when preparing engineering plans in small batch Enterprises:

(1) produced products. This product has been produced in our factory, and it can be accurately determined by drawing number, product name and relevant product characteristics; There are also cases where the drawing number or name is inconsistent, but it is judged by analyzing the product characteristics and process requirements. Experienced planners know whether the process data and tooling of the product are stored in the factory, and then determine whether it is a regular product or an irregular product, so as to judge the difficulty of organizing production

(2) similar products. By analyzing the product characteristics and process requirements, it can be determined that this product is similar to a product produced by our factory, and the existing process data and tooling can be used after adjustment

(3) new products, that is, the first products produced by the enterprise. Special treatment must be given to new products that are difficult in process design and tooling manufacturing and complicated in production technology and process

in an information-based production management system, product feature database (hereinafter referred to as product feature database) can be formed by collecting and refining the product and process information accumulated in daily work. When preparing the engineering plan, by inputting certain product feature information, if the same or similar product and process information can be extracted from the product feature library or the current engineering plan library, the engineering plan and reference process of the new project can be formed directly or through adjustment

2. The data structure of the product feature library

the data structure of the product feature library is basically the same as that of the engineering plan library. According to the description of the conceptual model of the relational database, the basic data structure of the product feature library is: product features (Engineering number, engineering category, product name, drawing number, material, reference Engineering). Among them:

① project number, as a product feature, which areas need to be tested for the safety performance testing of the French automotive industry? Keyword with 2n load

② project category, which is used to determine the management attribute of project construction

③ product name, at the same time, it can have product alias, and its superior classification is product category

④ drawing number, the drawing number of the product, is unique and can be used as an auxiliary keyword for the characteristics of the product

⑤ material determines the overall or main material requirements of the product. In order to facilitate production statistics, it may also be divided into multiple levels of material categories

⑥ reference project, the process characteristic information of a project extracted from the current process library or the reference process library. These features can be the same or similar. Generally, the drawing number is used as the basic keyword, including the quantity of parts, the demand for materials and spare parts, and the basic process. For products without drawings or regular production, the project number formed in the project plan will also be used as an auxiliary keyword to establish the connection with the reference project

II. Replace the process route library with the reference process library

1 Formation and use of reference process library

after the project plan is issued, if the project has provided reference projects, relevant processes will be extracted according to the reference project number. At the same time, regardless of whether a reference project is provided during the preparation of the project plan, the technician in charge can use the engineering characteristics of the project to extract the reference process from the current process library or the reference process library to form the process information of the current project. In such process design, the final process design is for the technologist. The information stored in the information system is only reference and shared information. The reference process library is also formed by copying and transferring the current project and process information by the technician in charge according to the production needs

when using the reference process library or the current process library to carry out the process design of new projects, it is faced with the problem of upward rounding magnification calculation and manual adjustment. This is because there is a certain proportional relationship between the commissioned quantity of the new project and the commissioned quantity of the reference project, but there will be a situation that is not an integer multiple relationship. At this time, the automatic proportional calculation of the number of parts, estimated working hours and estimated weight can only be rounded up, that is, the integer multiple rounding calculation greater than the magnification. For such automatic proportional calculation, the craftsman needs to make the final adjustment according to the actual situation, In order to ensure the rationality of the number of parts, working hours and weight

2. Structure of reference process library

generally, the current process library and reference process library have the same data structure, with product drawing number and parts drawing number as keywords, and the engineering number and parts number of the referenced project as auxiliary keywords. Although the differences in production characteristics and management habits of different enterprises are very obvious, their work figures show that the data structure of the impact experiment machine art library is basically a group of tables as follows:

① parts decomposition (Engineering number, part number, part drawing number, quantity, unit of measurement, specification and model, technical performance, material, process requirements description, and material supply unit)

② each professional process (professional category, project number, part number, process (process number, process name, estimated working hours, processing instructions, completion time))

③ material spare parts demand details (Engineering number, part number, material, specification and model, technical performance, weight, demand time)

generally, the professional categories can be divided into processing, wood mold, casting, forging, structure, heat treatment and assembly

in the reference process library, the keyword is the combination of Engineering number and part number, and engineering number is the key to connect with the product feature library. Auxiliary keywords are product drawing number and parts drawing number. The material supply unit determines the basic order of the supply of various parts and processes in a project from the outside of the enterprise to the internal circulation of the enterprise. The process in the processing technology and the components in the structural technology are sub data items in the basic technology, which is a "one to many" data structure. For the same part, only one of the three types of semi-finished product process can be selected: casting, forging and structure, while processing, semi-finished product and heat treatment may be required

the basic idea of the design of product feature library and reference process library is to strive to use the same, similar or similar information, so as to achieve simple and standardized operation by users, so as to achieve the purpose of higher degree of standardization and practicality of information as far as possible. Through the collection and storage of existing production management information, the continuous accumulation of information with similarities and similarities, make full use of the information of current products or historical products, and maximize the use of these information through selection, replication, reference, adjustment, etc., so as to improve the level of production management

third, we can add some cleaning agent to clean the business process design method of strict combination

for products with urgent construction period requirements, poor process requirements and construction management standardization, if the production is organized in strict accordance with the order of engineering plan, process design, production plan, construction operation plan, quality inspection and delivery, material spare parts or semi-finished products, It is possible to delay the normal production due to the untimely or error of information login in a certain link. Therefore, we should adopt the management and control method of Combining Leniency with strictness and moderation of leniency and strictness, adhere to the necessary strictness, and provide sufficient flexibility. Based on the principle that information is the tool of production management and production management system should not restrict production, the flexibility and practicality of business process design in the production management information system of small batch enterprises must be the first consideration

in the process of production plan, construction operation and quality inspection, the engineering plan and current process are the binding information that must be strictly observed by the construction operation, and the construction operation without engineering plan and relevant process information is not allowed. However, the preparation and issuance of the production plan may not be timely or inconsistent with the current capacity of the production workshop, and it may be necessary to organize the construction of the workshop through temporary manual instructions. Similarly, the quality inspection of semi-finished products or finished products does not require a construction plan. As long as the products in the project plan can be inspected and delivered to the warehouse according to the process requirements

with the delivery of finished products to the warehouse and customers, project management has entered the project settlement link. The project settlement marks that some or all of the project products have passed the product qualification inspection and handed over to the warehouse, and have obtained the product certificate issued by the customer. Therefore, the project settlement sheet can be prepared. When all the products of a project are settled according to the commissioned quantity required by the project plan, it marks the end of the internal production process of the project

based on the project settlement and the customer's payment, part or all of the financial settlement of a project can be carried out, so as to complete a customer order

the relationship of each link in the whole production management business process can be divided into strict control relationship and reference prompt relationship according to the possible tightness. By setting the switching function in the design and operation of MES