You can avoid having to manually retype a bill of materials by using CAD software that automatically generates the bill of materials from the 3D model. Every part you place in your design comes with its own properties, such as material, dimensions, and part number. The software reads this data and immediately uses it to build a complete bill of materials. In this article, we answer the most frequently asked questions about automatically generated bills of materials, from how they work technically to how they integrate with your ERP system.

Why isn’t a bill of materials generated automatically from a drawing?

A bill of materials is not automatically generated if the CAD software does not have a link between the drawing and the underlying model, or if the parts in the model do not contain structured properties. Without that link, the drawing is merely a visual representation, not a data source that the software can draw from.

This problem is common with traditional 2D drafting software, where the drawing and the bill of materials are two completely separate documents. You draw a part, but the software doesn’t know what it is, how much it weighs, or what material it’s made of. You then have to manually enter that information into a separate document or spreadsheet, which is time-consuming and prone to errors.

With modern 3D CAD software, things are different. As soon as you build a model from individual components and assign the correct properties to those components, the software has all the information it needs to automatically generate a bill of materials. The drawing is then no longer the final product, but a representation of a more information-rich model.

What is the difference between a linked bill of materials and a standalone bill of materials?

A linked bill of materials is directly connected to the 3D model and is automatically updated whenever you modify the design. A standalone bill of materials is a separate document that you create and maintain manually, independent of the model. The difference lies in the degree of automation and the likelihood of errors.

With a linked bill of materials, you don’t need to keep separate records. When you add a part to your model, it automatically appears in the bill of materials. If you remove a component, it also disappears from the list. This prevents your bill of materials from falling behind your design, which is a common source of errors in practice.

A standalone bill of materials does not offer that advantage. You have to manually update the bill of materials every time the design changes. That takes time and increases the risk that the list will no longer match what actually needs to be produced. For companies in the manufacturing industry, where custom work and frequent adjustments are the norm, a linked bill of materials is therefore the only viable long-term solution.

How does CAD software automatically generate a bill of materials from a 3D model?

CAD software automatically generates a bill of materials by extracting the properties of each part in the 3D model and compiling them into a structured overview. Each component in the model serves as a data carrier: the software collects the data and converts it into an exportable document.

The process works as follows. When you build a 3D assembly from individual parts, the software assigns a set of properties to each part. These include the part number, material type, dimensions, and quantity. When you generate a bill of materials, the software scans the entire assembly, counts the parts, and presents the result as a clear, organized list.

Modern CAD packages also offer the ability to display the bill of materials directly within the drawing, ensuring that the list is always up to date with the current state of the design. When you modify the model, the bill of materials in the drawing updates automatically. This completely eliminates the need to manually retype data.

What information must a part include to ensure an accurate bill of materials?

To ensure an accurate automatic bill of materials, each part in the 3D model must include at least a part number, a description, the material, and the quantity. Depending on your production process, additional information such as dimensions, weight, or a supplier reference may also be required.

The more complete the properties of a part are, the more useful the generated bill of materials will be. A list containing only part numbers and quantities is a start, but for purchasing, production, and inventory management, you generally need more information. Consider the following basic data for each part:

• Item number for unique identification
• Description so that everyone involved in the process knows what the component is
• Material Type for Purchasing and Production
• Dimensions such as length, width, and height
• Quantity per assembly
• Supplier Reference for Purchasing

It is a good idea to establish a standardized naming convention and structure for these properties within your company. Consistency in how you name and describe components ensures that the generated bill of materials always has the same structure and is immediately usable for the rest of your business process.

Can an automatic bill of materials be sent directly to an ERP system?

Yes, an automatically generated bill of materials can be sent directly to an ERP system, provided that the CAD software and the ERP system support an integration or share an export format that the ERP system can import. This prevents duplicate data entry and reduces the risk of errors in order processing.

The most common method is direct integration, in which the bill of materials is exported from the CAD software as a structured file—for example, in XML or CSV format—that the ERP system processes automatically. Some software vendors also offer a direct API connection, allowing the transfer to take place fully automatically without any employee intervention.

The benefits of such an integration are significant. As soon as a design is approved, the bill of materials is immediately forwarded to purchasing and production planning. No manual retyping, no delays, and no risk of the wrong version of a bill of materials going into production. For companies that operate with short lead times and a high volume of custom work, this represents a significant time savings.

Which CAD software automatically generates a bill of materials for the manufacturing industry?

CAD software that automatically generates a bill of materials for the manufacturing industry is available, among other options, in packages specifically developed for assembly-based 3D design. Examples include software that uses parametric or direct modeling techniques, in which each part is assigned its own set of properties that form the basis for the bill of materials.

For companies in industries such as furniture and interior design, metalworking, and mechanical engineering, there are specific solutions that not only generate bills of materials but also additional outputs such as cutting lists, purchase lists, and NC codes. This significantly shortens the path from design to production. Explore the available solutions by industry to see which features are relevant to your sector.

When choosing a CAD package for automatic bills of materials, it is wise to consider the following points:

• Does the software support linked bills of materials that automatically update along with the model?
• Can the bill of materials be exported to the format required by your ERP system?
• Is it possible to add custom properties to parts?
• Does the software also provide additional output, such as cutting paths or NC codes?

How IronCAD Helps with the Automatic Generation of Bill of Materials

IronCAD is a 3D CAD solution specifically designed for the manufacturing industry, in which the automatic generation of bills of materials is an integral part of the design process. You don’t have to manually retype any data, because the software links all part information directly to the 3D model. Specifically, IronCAD offers the following:

• Automatic bill of materials generation from the 3D assembly, always in sync with the current design
• Customizable part information so you can decide which details appear in the bill of materials
• Export options to common file formats for direct processing in an ERP system
• Additional output such as cutting lists, parts lists, and NC codes for a fully automated production process
• An intuitive interface that lets you get started quickly, even without extensive CAD experience

Would you like to see how IronCAD works in practice for your company? Contact us, and we’d be happy to show you what’s possible.