AutoCAD has no tools to manage bills of materials! right? Well, yes, well no, well… maybe sort of?

AutoCAD Bills of Materials

In this continued look at bills of materials (BOMs), let’s dive deep and see the AutoCAD tools we can use to generate and maintain lists of objects. So yes, AutoCAD does not have dedicated BOM tools, but there are enough options to fake it.

What tools am I talking about? How about the new Count feature? Or the Data Extraction tools? Blocks with attributes are essentially the same as 3D models with meta-property data.

Blocks and Attributes

AutoCAD Blocks group objects into a single entity. As a singular object, it is easier to select, manipulate, and share across drawings. Using blocks leads to consistency and standardization as the same symbol is used across all drawings. Attributes provide the ability for variable text metadata across your blocks. Each instance of a block definition can contain different attribute text content.

Creating blocks is easy. Use the BLOCK command to set the name, select the objects (including attribute definitions), and set the insertion point. By selecting the attribute definitions they automatically become part of the block, ready for use on the first insertion.

How does this help with bills of materials? It allows you to take unrelated 2D objects, group them into a singular named object, and specify descriptive metadata about each one. So instead of lines, arcs, and circles you now have countable objects representing the parts you manufacture and purchase.

Counting Blocks

AutoCAD’s COUNT is sort of a BOM tool. With this feature, AutoCAD quickly counts the instances of any object type within the drawing, including blocks. Insert a field with the count data or a table listing the blocks, which updates with changes to the drawing.

After starting the feature, select the objects to count. This initiates the count environment, with the Count toolbar along the top of the drawing area. Use this toolbar for a quick reference to the number of objects, to navigate between the objects in the count, to insert the count field, and to end the counting process. When selecting a single object, all objects of that type and configuration are automatically selected. When selecting multiple objects, AutoCAD looks for identical instances of the same object combination.

AutoCAD Count Blocks

Use the List All Blocks option for the Count palette to list the blocks, with the number of instances, contained with the drawing. Select a block to drill into the selection. It’s in the right-click menu where you’ll find the option of inserting a Count Field. Use the palette option to insert a table.

AutoCAD Count Insert Table

What about blocks with varying attribute information? Within the Count palette, you can expand the block by property or attribute value. This allows you to see instances group by common properties.

AutoCAD Count Expanding by Property

So Count is sort of a bill of materials tool. Although it provides the block name, count, and one subsequent property, you need to provide the descriptions and other block details. Do not dismiss this tool though, it provides a quick way to get quantities, say to figure out ordering details.

Bills of Materials from Data Extraction

For AutoCAD Bills of Materials generation, the creme-la-creme is Data Extraction.

This wizard extracts information from objects, including block attributes and drawing properties. Send the information to a CSV spreadsheet or insert it as a table into the drawing.

The process:

  1. Create new or select an existing Data Extraction
  2. Specify the data source(s)
  3. Select the objects
  4. Select the properties
  5. Refine the properties
  6. Choose the output

The data extraction (.dxe) is the saved configuration. It only needs to be created once as you can use this as a template as opposed to re-establishing the settings each time.

The data source is a portion of a drawing, the active drawing, or a selection of drawings. You choose to include blocks and/or to include objects from xrefs.

AutoCAD Data Extraction Define Data Source

When selecting the objects, use the options to quickly filter the data including showing only blocks with attributes. A key feature is an option to adjust display names, allowing for the merging of like objects with different names. For example, blocks representing different views of an item (front, top, side, etc).

AutoCAD Data Extraction Select Objects

For a bill of materials hide the name column (unless the name represents an important property) and enable Combine identical rows.

AutoCAD Data Extraction Refine Data

Note, externally exported data extractions do not auto-update with changes to the drawing. You will need to re-export the details.

AutoCAD Data Extraction Choose Output

With changes to the drawing use Update All Data Links, to update the data extraction and associated tables.

AutoCAD Update All Data Links

Managing AutoCAD Bill of Materials

As you can see, AutoCAD provides basic bill-of-material-like-tools for the presentation of components represented in your drawings. Count provides a quick and convenient method to extract the number of instances, useful for ordering. Data extraction creates a more traditional bill of materials, listing the component’s description, part number, and other key attributes.

With the lack of true BOM tools within AutoCAD, there are limitations. There is no eloquent method of ballooning tieing the balloon item number to the parts list, there is only a single view of the BOM, and AutoCAD provides no BOM integration with Vault or PLM. The setup of blocks is time-consuming as you need to ensure each block definition uses the same set of attributes. Without this, there is no way to extract the bill of materials.

Feature image from picjumbo