BOM builder. See where the cost sits.
A bill of materials (BOM) lists every part, material and process needed to make one finished product, with quantities per parent and costs. Edit the example or start your own and this builder rolls costs up through three levels, shows the cost per unit and per batch, ranks the top cost drivers and exports a CSV.
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Cost by sub-assembly
Top cost drivers
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Three steps. One clear answer.
- 01
Replace the example rows with your parts: level, part number, description, material, process, quantity per parent, unit, unit cost and preferred region.
- 02
Add, remove or move rows; set the level to 1 or 2 to place a part under the assembly above it.
- 03
Read the cost per finished unit, the batch cost and the top cost drivers, then download the CSV or copy the BOM as text.
Each row's parent is the nearest row above it with a lower level. Quantity per finished unit = quantity per parent × the quantity per finished unit of its parent (level-0 rows use their own quantity). Extended cost = unit cost × quantity per finished unit. Rolled-up cost of an assembly = its own extended cost + the extended costs of every row below it until the next row at the same or a higher level. Cost per finished unit = the sum of all extended costs; batch cost = cost per unit × units to build. Costs are ex-works material and conversion costs, before freight, duty and margin.
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Straight answers.
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[email protected]What is a multi-level BOM?
A BOM that nests parts under the assemblies they belong to. Level 0 is the finished product, level 1 its sub-assemblies and direct parts, level 2 the parts of each sub-assembly. It shows both what to buy and how the product is built.
How do I enter a part used in fractions, like a carton for 24 units?
Enter the quantity per parent as a decimal: one carton for 24 bottles is 1 ÷ 24 = 0.0417 cartons per bottle. The cost then spreads correctly across units.
What should the unit cost of an assembly be?
Only the cost added at that step, such as assembly labour, coating or packing. The parts below it are added automatically in the rolled-up cost, so they are not counted twice.
Can I open the CSV in Excel or Google Sheets?
Yes. The file is UTF-8 CSV with a header row, including quantity per finished unit, extended cost and rolled-up cost for each line.
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