A quote arrives in production: "Fence 23 m, anthracite, 1.5 m high, 1 m pedestrian gate." A colleague in production picks up a pencil and starts counting. How many fields, how many posts, how many caps and brackets. The salesperson counted exactly the same things yesterday, to work out the price.
The quote is fine. The customer can see what they are buying and for how much. What is not fine is that the counts behind the price disappear on the way to production, and someone has to work them out again.
A bill of materials (BOM) is the list of parts and their quantities needed to make one product. For a made-to-order product the bill of materials changes with every order. Most of its figures, though, have already been counted once by whoever worked out the price, because a made-to-order price is built from those counts.
What a bill of materials is, and its types
A bill of materials says what a product is made of: part, quantity and unit. For a fence that might be the field infill, the post, the post cap, brackets with screws and the anchor. Depending on what it has to capture, it can be:
- A single-level BOM: the parts of one product listed one under another, with no further breakdown.
- A multi-level BOM: shows sub-assemblies too. A gate is one line in a fence, but it has its own frame, infill, hinges and lock.
- An engineering BOM: created during design, usually in a CAD program, describing the product as drawn.
- A manufacturing BOM: describes the product as it is made, with cuts, semi-finished parts and the order of steps.
A bill of materials and a specification are not the same thing. The specification says what the customer wants: sizes, colour and add-ons. The bill of materials says what production builds it from.
The same fence, counted twice
In made-to-order work the bill of materials usually starts life from the quote, by hand. It costs you in these places:
- The salesperson counts for the price. Fields, posts and gates, because without them there is no price.
- Production counts for materials. The same fields and posts, from the same quote, with a different pencil.
- Purchasing waits. Materials are ordered only once production has finished counting. With profiles on long lead times, that is a second wait.
- The mistake turns up on site. Nobody looks for a missing post in the office. The installer finds it on the customer's plot, drill in hand.
- A change halfway through. The customer extends the fence by two fields. The salesperson changes the price, and production hears about it on the phone, if it hears at all.
Nobody is doing anything wrong here. A quote is a document for the customer, and production takes from it what it needs. It just does so by hand, for the second time.
Why the price and the bill of materials come from the same counts
A made-to-order product cannot be priced accurately without someone counting what it is made of. A calculator that multiplies metres by a rate skips that step. That is why it shows a different amount from the one in the quote.
A configurator cannot skip it. The existing fence engine divides each side of the fence into fields, adds one more post than there are fields on a straight run, and adds a gate's own posts beside it. It then builds the price from lines with quantities: the infill for each field by its size, fixings per field, the post, cap and anchoring per post, and gates with their add-ons per piece. How a fence is divided into fields is covered in Fence configurator for manufacturers.
Those lines are the first level of a bill of materials. From them, production knows how many fields, posts, caps and sets of fixings to prepare, with no pencil and no second count.
What changes when the counts are made at the enquiry
When the configuration carries the part counts from the start, they travel the whole way with it.
Production gets the same figures as the quote
The counts come from the same configuration as the price. The quote and production read one source and cannot drift apart.
Purchasing can start sooner
Materials can be ordered as soon as the order is confirmed. Nobody waits for someone in production to find time to recount.
A change to the configuration changes the counts too
When the customer extends the fence by two fields, the price and the number of fields and posts are recalculated together. Production does not hear about the change on the phone; it sees it in the specification.
Installation knows what should be in the van
Before setting off, the installer has the list of parts for the job. The tape measure stays in the van as always; the missing post does not.
Where the configurator ends and production begins
The configurator counts the parts the price is built from. A manufacturing BOM goes further: cut lengths, semi-finished parts, screws per piece, packaging. Your production knows those rules, and they live in its drawings or in the ERP.
How much of that the configurator should hand over depends on your process. A configuration can be saved to treede CRM with its specification, contact details and a link. Further fields and steps, such as a parts breakdown, are confirmed at deployment. A connection to your ERP is designed individually around its interface; the systems are listed under integrations.
Where CPQ sits in the whole process, and where the ERP does, is covered in What is CPQ?.
When it isn't worth taking the bill of materials from the configuration
Not every firm needs one. In these situations the quote and a pencil are enough:
- Production draws every job in a CAD program. The bill of materials then comes from the drawing, and the configurator only supplies the specification.
- You sell finished products from stock. There is one bill of materials per model, and it does not change with the order.
- You get a handful of jobs a month. A manual count is quicker than any setup.
If none of these describes you, read on.
A five-minute test: how many times is a fence counted at your firm?
Take your most recent job and answer four questions:
- Who counts the parts for the price, and who for production? If two people, it is counted twice.
- How does production learn about a change to the order? If by phone, the bill of materials is always a step behind.
- When are materials ordered? If only after production recounts, purchasing is waiting on a pencil.
- How many installations last month waited for a missing part? Each one is an extra trip.
The first step takes five minutes: put your last quote next to its production sheet and circle the figures that appear on both. Those only need counting once.
Where a bill of materials from the configuration pays off
Mostly with products built from repeating parts in quantities that follow the size:
- Fences and gates: fields, posts, caps, fixings and gates.
- Pergolas and shelters: posts, beams, louvres and blinds.
- Verandas and conservatories: rafters, glass panes and profiles.
- Garden buildings and saunas: walls, cladding, windows and doors.
The full list of 305 product types is in the configurator catalogue.
Frequently asked questions
What is a bill of materials?
A bill of materials is the list of parts and their quantities needed to make one product. It can be single-level or multi-level with sub-assemblies, and, depending on its purpose, an engineering or a manufacturing BOM.
What does BOM stand for?
Bill of materials. The abbreviation is used in English-speaking firms and widely elsewhere, including in Slovak and Czech workshops.
What is the difference between a bill of materials and a specification?
A specification describes what the customer ordered: sizes, colour and add-ons. A bill of materials describes which parts, in what quantities, production will build it from.
What now
And the pencil in production? It can stay on the desk for notes. The fields and posts have already been counted once by whoever did the price; they only need passing on.
See what a configurator costs, or send us your parts price list and we will show you which counts come out of a configuration for your production.
