BC
BOMCost

Bill of Materials Explosion

The Workshop That Ordered Legs for an Army of Stools

A story about Borden Woodworks, in Millhaven — and how BOMCost's bill of materials explosion put an end to shop-floor arithmetic.

The order that came in on a Friday afternoon

Borden Woodworks makes bar stools, dining chairs and the odd bookshelf out of a converted barn on the edge of Millhaven. Daniel Borden built the business from a single lathe fifteen years ago, and he still prices, cuts and assembles every batch himself — including the arithmetic. When the Birchgate Hotel called on a Friday afternoon needing forty-five bar stools for a new rooftop bar, in time for a launch three weeks out, Daniel didn't reach for a spreadsheet. He reached for a pencil and the back of a cutting list.

Each stool takes one set of three steel hairpin legs, a pine seat panel, sixteen wood screws, a splash of glue, foam padding and a stretch of upholstery fabric. Forty-five stools, three legs each: 135 legs. Daniel did that part correctly, in his head, between measuring a seat panel and taking the hotel's call. It's what happened next, on the phone to the steel supplier, that went sideways.

The people in this story

DB

Daniel Borden

Owner. Has priced every batch by hand for fifteen years — usually without a hitch.

PS

Priya Shah

Shop hand. Took the supplier's call and placed the order exactly as it was given to her.

OC

Owen Castellan

Procurement lead, Birchgate Hotel. Just wanted forty-five stools by opening night.

RT

Reg Talbot

Steel supplier. The only person in this story who had a genuinely great week.

"Sets" and "legs" are not the same word

Reg Talbot sells hairpin legs two ways: loose, by the leg, or bagged in threes as a "set" — same part, same price per leg, just packed differently for people who don't want to count out three of everything by hand. Daniel had done the multiplication correctly — 135 legs — but when he read the number down the phone to Priya to place with Reg, he said "a hundred and thirty-five sets." Priya wrote it down exactly as told. Reg, who had no way of knowing Daniel meant loose legs, packed and shipped a hundred and thirty-five three-packs: 405 legs, three times what a batch of forty-five stools could ever use.

Nobody had made an arithmetic mistake. Everybody had done their own part correctly. The steel simply changed units once, quietly, somewhere between a workbench and a phone call, and came out the other end tripled.

"The invoice said four hundred and five legs and I remember just laughing. We had steel stacked against every wall of the barn for a job that needed a third of it. Reg still brings it up." — Daniel Borden, Borden Woodworks

How a bill of materials explosion stops the mix-up before it ships

Borden Woodworks now keeps its bar stool build defined once in BOMCost: every raw material, in its own real unit — legs, not sets; screws, not boxes; fabric by the metre, not the roll. When a rush order comes in, Daniel enters the quantity of stools needed, and BOMCost explodes the bill of materials on its own, in the unit each supplier actually ships in, and hands back the exact purchase list. No cutting-list arithmetic, no reading a number down a phone line, no unit quietly changing meaning between a workbench and a warehouse.

And if the build changes — a different leg supplier, one screw fewer per seat — Daniel updates it once, in one place, and every order after that comes out right without anyone having to remember the change.

Illustrative only

Birchgate Hotel — rush order

Bar Stool×45
→

Raw materials needed (calculated)

Steel Hairpin Legs
Pine Seat Panel
Wood Screws
Upholstery Fabric

Change the order size, and the purchase list recalculates itself — always in the unit each supplier actually ships.

Twelve stools or a hundred and twenty — it's the same one number

The stool didn't change, and Daniel still cuts every seat panel himself. What changed is the order: today, any batch size is one field in BOMCost, and the purchase list comes back already in legs, screws and metres of fabric — never a number that quietly means something different by the time it reaches a supplier. Reg still gets the occasional large order. He just doesn't get one three times too large any more.


The bill of materials explosion is part of BOMCost, where Borden Woodworks also tracks its raw material catalogue, costs every product against current supplier prices, and plans production runs — all from the same bill of materials, entered once.

Does your shop floor still run on cutting-list arithmetic?

A furniture workshop, a metal shop, a small production line — the bill of materials explosion works the same way, on your own products and your own suppliers' units.

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