4.2 According to the design software
4.2.1 BOM in CAD
The design department is both a designer of the BOM and a user of the BOM. Single parts such as drawing number, material name (material type such as 45 steel), weight, volume, design modification audit number, material effective date, etc.; components or components also include external parts, purchased parts, general parts, Standard parts, borrowed parts, assembly quantity of each single part, part drawing number, etc.; general drawing (assembled by parts, component parts, etc.) also includes packaging, parts list, technical documents, product manuals, warranty documents, etc. These are all part of the BOM information.
In the design department (CAD), the so-called BOM is actually a parts list, which is a technical document that focuses on product information aggregation.
The design department organizes BOM information by the number of the product of a certain type. After receiving the order, the design department will follow the order requirements. Under normal circumstances, there are three design ideas: top-down form design, bottom-up form design, and middle-to-two form design.
Regardless of the design method, the organization of the figure number is consistent. The product information is combined according to the figure number, and the total schedule, standard parts summary table, purchased parts summary table, and external parts of the product are formed. Summary tables, etc., can also generate product drawing catalogs when needed (for customers or outsourcing factories that do not run ERP systems).
Sometimes an identical part has different drawing numbers because it belongs to different products, so it is not necessary to consider the uniqueness of the enterprise material coding. It should be noted that after forming the bill of materials, each material has a unique code, that is, the material number. Do not confuse parts lists (CAD as a BOM) with BOM information in ERP.
The parts detail information table in the design department is transformed into the BOM information in the ERP system. It requires the cooperation of the design department, the process department and the production department, and the management of the product relationship characteristics of the PDM (product data management) design to solve the parts list and BOM. The similarities and differences between the tables, especially the inconsistency between the figure number and the code number (the PDM product structure module is completed by its rule base, variables and parts list functions).
In terms of use, whenever a product structure changes, or a customer changes a technical document, involves a quality issue, or redesigns a part, the design change notice must be notified to ensure the accuracy of the bill of materials. in accordance with. Under the guidance of the design change notification document, the design department obtains information on all parts and their structural information through the BOM information table.
Only by obtaining this information can it be defined, described or modified so that production can run normally (especially the customer's urgent change notice). Based on the design change notification number, with PDM support, it is easy to retrieve change information and guide production activities such as production, shipping, and after-sales services.
In the actual production operation process, design changes are an important factor leading to data inaccuracy, so there must be a set of effective design change notification management methods to manage design change notifications. Since it involves sales, procurement, production, engineering, finance, and other departments, the design change notice is generally managed directly by the company's senior executives. This process is subject to five steps of identification change notification, analysis, approval, documentation and supervision. Part of the data generated by the design department (CAD) is processed by PDM and transmitted to the ERP system.
There are several concepts to be added about designing a BOM:
The components of the components on the product structure tree can be divided into three categories: standard parts, structural parts, and design parts.
The way the design parts are produced can be generated from different 3DCAD or 2D CAD schedules, and is produced by our factory or collaborative plant design.
Structural components can be photos or a simple sketch. The node names on the corresponding product structure tree are often product outline drawings, product size chain diagrams, product assembly relationship diagrams, packaging components, and so on.
This information must be reflected in many enterprise product structure trees, but this information cannot be obtained from the assembly drawing. For example, the product outline drawing and the product assembly drawing are acceptable if they are hung on the product node, but the user habit is often considered to be the product outline drawing. It is the same level as the product assembly drawing; in addition, the packaging subtree needs to be manually created after the packaging subnodes are expanded, and cannot be directly linked from the detailed table by BOM expansion.
General-purpose components include standard parts libraries and industry and enterprise general-purpose parts. And can be modified and deleted and merged, adding a common parts library to carefully check the process. Universal parts can evolve from borrowed parts.
The same product, its structural components, and sometimes even design parts or standard components can have many different options. Therefore, the same product in terms of manufacturing and sales quotation can have different product information structure combinations (such as price, batch, delivery date) for different customers.
However, these conditions are generally maintained in the ERP system, and the PDM system only needs to ensure the integrity and consistency of the underlying data.
