Counting Mode and Maximal Level in BricsCAD Mechanical Explained
Quick answer: Hierarchical BOM tables support two counting modes, confirming the Counting mode property covered on this hub’s BOM Manager page: Count all instances, the total number of subassemblies and parts across the entire assembly, and Count instances in parent component, the total within just the immediate parent (treated as the root component).
A Worked Example: The Tripod Assembly
The main Tripod assembly contains 3 Tripod foot assemblies, and each foot assembly contains 1 Bond assembly and 1 Tube assembly.
Count all instances:
| # | Component | Quantity |
|---|---|---|
| 1 | Tripod assembly | 1 |
| 1.1 | Tripod foot assembly | 3 |
| 1.1.1 | Bond assembly | 3 |
| 1.1.2 | Tubes assembly | 3 |
Count instances in parent component:
| # | Component | Quantity |
|---|---|---|
| 1 | Tripod assembly | 1 |
| 1.1 | Tripod foot assembly | 3 |
| 1.1.1 | Bond assembly | 1 |
| 1.1.2 | Tubes assembly | 1 |
Changing the Counting Mode
Count instances in parent component is the default, changeable in the BOM Manager or via BMBOM.
Before V20.2, every hierarchical BOM table defaulted to Count all instances instead. Tables updated in V20.2 or later automatically switch to Count instances in parent component, which can change some parts’ displayed quantities, set the counting mode manually in the BOM Manager if that’s not what you want.
Limiting a Hierarchical BOM by Maximal Level
By default, a hierarchical BOM shows every level in the model. The Max level property limits it to parts up to a given level, resolving the Limit by this level and Show all levels row context menu options covered on this hub’s BOM Manager page. With Max level set to 2, for example, only top-level components and the subcomponents directly inside them get listed.
Frequently Asked Questions
Why did my hierarchical BOM’s quantities change after updating from an older BricsCAD version? Tables updated in V20.2 or later automatically switch from Count all instances to Count instances in parent component, the new default, set it manually if you need the old behaviour back.
What’s the practical difference between the two counting modes? Count all instances tallies totals across the whole assembly; Count instances in parent component only tallies within the immediate parent, treating it as the root.
How do I stop a hierarchical BOM from showing deeply nested subcomponents? Set its Max level property to limit how many levels deep the table lists.
Where do I change a BOM’s counting mode? In the BOM Manager, or via the BMBOM command.