Optional Components
Some products have components that are included when available but shouldn't prevent a build when they're out of stock. Partsemble handles this with the optional flag on BOM entries.
When to Use Optional Components
Common scenarios:
- Branding or labeling — a company logo plate or asset tag installed when available
- Upgraded hardware — stainless hardware used when in stock, standard zinc-plated hardware otherwise
- Finishing touches — a decorative trim piece that's nice to have but not essential to the product
- Alternative packaging — a premium crate used when in stock, with standard pallet packaging as the fallback
The key test: if this component is out of stock, would you still build the product? If yes, mark it optional.
How to Mark a Component as Optional
When adding or editing a BOM entry, toggle the Optional flag on the component. Optional components are visually distinguished in the BOM with a label so they're easy to identify.
How Optional Components Affect Builds
Buildability
Optional components are excluded from the max buildable calculation. Only required components determine how many units you can build.
For example, with this BOM:
| Component | Qty | Stock | Optional? |
|---|---|---|---|
| Steel Panel | 1 | 50 | No |
| Hex Bolt 3/8" | 2 | 40 | No |
| Branded Nameplate | 1 | 0 | Yes |
Max buildable = 20 (limited by Hex Bolt 3/8": 40 stock / 2 per unit). The Branded Nameplate being out of stock doesn't reduce this number.
Cost Estimates
The BOM's estimated cost includes only required components by default. This gives you the guaranteed cost per unit regardless of whether optional items are available.
During Build Execution
When you execute a build, optional components are included if they're in stock. If an optional component has insufficient stock for the full build quantity, Partsemble consumes what's available and proceeds with the build.
If you want full control over whether optional components are included in a specific build, you can make that decision during the build preview step before executing.
Example
A metal fabrication shop makes an industrial enclosure. The BOM includes:
| Component | Qty | Optional? | Why |
|---|---|---|---|
| Welded Frame | 1 | No | Core structure |
| Door Assembly | 1 | No | Core component |
| Mounting Bracket Set | 1 | No | Standard hardware |
| Branded Nameplate | 1 | Yes | Customer-specific label |
The nameplate is optional because it's only applied on customer-branded orders. When nameplates aren't in stock, production continues without them. The buildability and cost calculations reflect the three required components only.