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How to Create a Custom Bill of Materials in 3D Mechanical CAD Systems

Every product designed in 3D mechanical CAD systems requires a Bill of Materials (BOM). It is an essential tool for planning production and purchasing.

BOMs can be embedded into SOLIDWORKS assemblies and drawings as Excel-based tables. When inserted, the BOM updates automatically.

Using an Excel template allows you to add additional columns, change column names and customize the BOM formatting.


A bill of materials is a document that lists all the parts, subassemblies, assemblies and components that are needed to manufacture a finished product. It also includes the quantities of each item. A BOM can help streamline the manufacturing process, enabling engineers to create a detailed product design in less time. CAD modelling software such as SolidWorks, Catia and Autodesk Inventor include the ability to make a BOM. However, the standard BOM templates often do not provide sufficient flexibility to meet all requirements. A free add-on called OpenBOM can help you customize your BOM to suit your needs.

BOMs can be inserted into an assembly drawing, or saved as Excel-based files. CAD BOMs automatically update as edits are made in the underlying assembly file. They can be used as a graphical reference or in table form, and they can be anchored, moved, split, or edited. In addition, they can contain configuration-specific values for items. BOMs can be inserted into both single-body part and multibody part documents.

Onshape’s cloud-based CAD collaboration and data management features facilitate teamwork and accelerate product development. When you insert a CAD BOM into an assembly drawing, the item numbers and quantities in the BOM appear in intelligent balloon callouts in the assembly drawing. These changes are reflected in the CAD model and in the BOM, and are visible to anyone who is granted access to the 3D model.


SOLIDWORKS Manage allows for robust reporting capabilities on BOMs. This makes it easy to output a BOM to a format that is useful to the target audience, such as Excel or an XML file. For example, a flat BOM that aggregates all the unique parts into a single list and rolls up their costs may save a purchasing team hours of time in Excel.

A BOM can also include a reference designator that helps users find the part in the CAD model. This is especially important for parts that will be fabricated into a printed circuit board. Adding this information to a SolidWorks BOM can reduce confusions and increase productivity. This can also help with inventory management, since it provides a quick way to find the required parts for a particular assembly.

In addition to a BOM, SOLIDWORKS Composer can also generate a table for technical documentation, including product specifications and data sheets. This can be helpful when presenting a product to a customer or using it in manufacturing.

All CAD modelling software includes the ability to make a BOM, but SolidWorks has a few additional features that make it stand out from its competitors. The program offers a ‘BOM Workshop’ that simplifies the process of creating a custom BOM or REV table. This can be accessed by selecting the ‘Workshops’ tab in the command ribbon and choosing ‘BOM’.


Most CAD modelling software offers the ability to create a bill of materials (BOM) which is essentially a list of ingredients required to build a product. It includes all the parts, subassemblies, assemblies and components as well as raw material required to manufacture a product. The BOM is a vital piece of data in a project and must be accurate at all times. This helps prevent any miscommunications between designers and the manufacturing team and ensures that a product is built exactly as it is designed.

The capabilities of the SOLIDWORKS BOM are extensive and include features such as dissolving subassemblies, displaying exploded views of parts, and listing dimensional data for weldment parts. Additionally, you can customize column layouts and run various commands from the BOM toolbar. You can also choose whether to display a computed or an actual BOM.

A computed BOM automatically updates whenever you make changes to components in an assembly or drawing. This includes adding, deleting, replacing, or renaming components, changing custom properties, and combining rows in a table. However, the computed BOM does not reflect BOM exclusions that you configure for a particular assembly or drawing.

BOMs can be inserted easily into drawings using the Insert Table command in the Toolbox tab. Several templates are available for you to select from, and you can modify these to suit your needs.


BOMs contain important information that needs to be protected. They also often need to be updated frequently, such as a change in supplier pricing or availability. This data needs to be securely stored and managed so that only authorized users have access to it. This type of security includes not only limiting who can view or modify a BOM but also protecting the integrity of the BOM’s information.

SOLIDWORKS Electrical Schematics Professional allows you to customize your BOM table in a number of ways, including adding columns and editing the format of the row and column headers. The program also enables you to add reference designators. These indicators tell the designer where that specific part will fit on a PCB, which can help to avoid errors and misunderstandings later on.

Another way to customize a BOM is to change the default part numbers that SOLIDWORKS assigns. These part numbers are used to identify the component in the assembly, and they can be either in an intelligent or non-intelligent format. Intelligent part numbers automatically update as the assembly changes, while non-intelligent part numbers require manual updating.

You can also modify the way a BOM displays in a drawing. To do this, double-click the BOM or right-click it and select Edit. To avoid losing text formatting, you should not edit a BOM while it is active. In addition, you should ensure that the “Row number follows assembly ordering” option is selected.