Build a bill of materials

A bill of materials is a recipe. It says what goes into one finished unit, and how much of each.

Write the recipe once and the app can answer a question you would otherwise answer by walking the shelves: how many of this could we build today. That number appears next to the product, feeds the build queue, and is part of what your storefront is told you have.

This page covers:

• What a bill of materials is
• Before you start
• Add the components
• Sub-kits and the depth limit
• What saving changes and what it does not

What a bill of materials is

One parent product, and the list of components one unit of it consumes.

Only a built product has one. Every product carries an inventory type, and the parts list appears only when that type is set to built — a plain stocked product holds units and has no recipe, and a service holds nothing at all. If the components panel is missing, the product's type is the first thing to check.

Each line is a component and a quantity per finished unit. A gift set made of one notebook, two pens and one sleeve is four lines, with quantities 1, 2 and 1.

Two extra things a line can carry:

• Wastage. A percentage added on top, for the share of material that gets spoiled in the making. A line with quantity 2 and 5% wastage consumes slightly more than 2 per unit, always rounded up.
• Notes. Free text for the person who reads the recipe next.

Before you start

Every component has to exist as a product first.

The component picker searches your catalogue and offers nothing else. There is no "add it anyway" escape hatch, and a bulk import rejects any row whose component code is not in the catalogue. This is deliberate: a parts list that names something the app has never heard of cannot be counted, costed or built.

So before you open the editor, have:

• The parent product, with its inventory type set to built.
• Every component already created, each with its own product code, for example SKU-001.
• The quantity of each component that one finished unit consumes.

If a component is missing, create it as a product first, then come back.

Add the components

1. Open the product and find the components panel. From the Bill of Materials page you can also open any built product straight into its editor.
2. Click Add component. A search box appears — type a product code or a name and pick from the results.
3. Set Qty needed. This is per finished unit, not per batch. Two pens in one gift set is 2, whether you build one set or a thousand.
4. Repeat for every component. Each component may appear only once, so combine duplicates into a single line rather than adding two.
5. Click Save BOM.

Alongside each line the editor shows the component's type, its unit cost, and how much of it is on hand and available. Those columns are read-only. They are there so you can see immediately whether the recipe you just wrote is one you could actually build.

The whole list saves at once. There is no per-row save — the button replaces every line in one go, so a half-written list never lands. Remove a row and save, and that component is gone from the recipe.

Importing many at once

For a large catalogue there is a CSV import on the Bill of Materials page. One row per component line, with columns for the parent code, the component code, the quantity required, the wastage percentage and a note. Same rules apply: an unknown component code is rejected rather than quietly skipped.

Sub-kits and the depth limit

A component can itself be a built product. That is a sub-kit, and it is normal.

When it happens, the app counts the sub-kit twice over: the finished sub-kits sitting on the shelf, and the ones that could still be built from their own parts. A sleeve line backed by 20 finished sleeves and the parts for 60 more supports 80 parents, not 20.

Three rules keep the tree sane, and all three are checked when you save:

Six levels is a lot. If you are pressing against it, the model is usually telling you that two of the middle layers are the same idea.

One more thing decides whether a component limits you at all. A component set to build on demand holds no stock by design, so it never caps the count. If every component on a recipe is on demand, the product reads Always available instead of a number.

What saving changes and what it does not

Saving a parts list moves no stock. Not one unit.

What it changes is what the app believes. Immediately after you save:

• The product gets an assemblable figure — how many complete units the components on hand could produce right now.
• The limiting component is named: the one line that runs out first. Restocking anything else changes nothing.
• The product is bucketed on the Bill of Materials page as blocked, constrained by stock, always available, or missing a parts list entirely.

That assemblable figure is location-aware, and this catches people out. The components have to be in the same place as each other for the count to be real. Twenty sleeves at a retail counter and twenty notebooks at your main warehouse build nothing, because nobody is assembling at either end with half the parts.

Stock only moves when someone actually builds — that happens on an assembly order, not here. And a built product is always three numbers, not one: the units already built, the units its components could still make, and what is left over after what is already promised to orders. The house way of saying it out loud is "we have 25 in stock, and the components to assemble 50 more."

Explore

Running the build. The parts list is the plan; an assembly order is what actually consumes components and puts finished units on the shelf. Learn more →

The three numbers. Why a built product reports on hand, assemblable and available separately, and which one your storefront sees. Learn more →

Types and modes. Which products get a parts list at all, and what "on demand" does to the count. Learn more →