Creating a Bill of Materials for Electrical Work: Manual vs. Software
A complete bill of materials decides whether a project earns margin or runs at a loss. Manual counting misses every 20th component — software gives you an inspection-ready BOM in minutes. This guide shows the path to the perfect BOM.
Why BOMs are critical
Calculation
No reliable quotation without a precise BOM. Missed line items eat into the margin.
Material ordering
A single list per project prevents duplicate orders and supply gaps on site.
Documentation
For E-check and system documentation, the BOM is part of the required documents.
Warranty
When defects occur, traceability of installed components matters — the BOM is the source.
What a good BOM contains
More than just quantities — a real BOM documents everything that matters later.
Article number and manufacturer
Unique identification for ordering and proof.
Quantity
With unit (piece, meter, set) and reserve.
Unit price and total
Current wholesale price and list price for calculation.
Installation location
Where exactly in the project — room, circuit, position.
Category
Protective devices, switchgear, cables, installation material.
Supplier
When using multiple wholesalers: who supplies which item cheapest?
Manual vs. software-generated
Manual BOM
- No software needed
- Full control
- High time investment (hours to days)
- High error rate (5-10 %)
- Complete recalculation on changes
Software BOM
- Generation in seconds
- Current prices via interface
- Automatic updates on changes
- Software license required
- Onboarding to the tool
The ideal BOM workflow
1. Installation plan complete
Only when every current path, socket and switchgear is in the plan is the BOM worth it.
2. Generate BOM automatically
Software walks all devices and connections, summing quantities per article.
3. Add reserve
5-10 % reserve on consumables like terminals, screws, cable ends.
4. Compare suppliers
Use wholesaler interfaces: the same article often varies in price.
5. Generate order
BOM directly as an order to the wholesaler portal — no manual retyping.
Common BOM mistakes
Installation material forgotten
Terminals, plugs, screws, cable ties add up. Anyone not capturing these underbids themselves.
Reserve forgotten
On site you always need 5-10 % more — otherwise re-ordering.
Prices not current
Copper prices fluctuate. Anyone calculating with old prices loses money on every order.
Conclusion: software pays off from the first project
Manual BOMs are no longer state of the art. Even small shops save 5-10 hours per project with software — and calculate more precisely.
💡 Tip: Look for tools that integrate wholesaler APIs (Sonepar, Famo, Rexel) directly. Saves another hour per project.
Create BOM automatically
myElectricPlan generates a BOM with article numbers and prices automatically from every installation plan. Wholesaler interfaces included.
Generate BOM now