> For the complete documentation index, see [llms.txt](https://help.besmart.software/older-26.0.0/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.besmart.software/older-26.0.0/commands-overview/bom/sync.md).
# Sync
## Command Description
The Sync command copies the item numbers of the *Structured* BOM view of the current (main) assembly to the *Structured* BOM view of the subassemblies.
{% hint style="info" %}
This command modifies components' item numbers in subassemblies.
{% endhint %}
{% hint style="warning" %}
This command is to be run in the main assembly only.
{% endhint %}
A schematic image of the process is in the image below.
Sync command workflow
### Summary of changes to the BOM performed by the command (a comparison matrix)
The comparison matrix of BOM manipulation tools
## Command Location
* Assembly environment (`Holixa T4I -> BOM panel`, `Assemble -> Manage panel`).
## Command Settings
This command has no settings.
## Workflow Overview
1. Run the command.
## Description of changes performed by the command
In the *Structured* BOM of the main assembly, components 004, 005, and 006 have item numbers 4, 5, and 6 (after the dot symbol). Item numbers of components 004, 005, and 006 in the structured BOM view in subassembly 010 are 1, 2, and 3.
| Structured main assembly BOM before applying the command | Structured subassembly BOM before applying the command | Structured subassembly BOM after applying the command |
| -------------------------------------------------------- | ------------------------------------------------------ | ----------------------------------------------------- |
|  |  |  |
After running the command, structured numbering in the subassembly matches the structured numbering (behind the dot symbol) of the main assembly. The subassembly file is physically modified by the command.