Planning stock
Kits: build ahead, or sell as a kit?
Two ways to track something made of other things, and how to choose between them.
On this page
The choice is about stock, not about selling
| Question | Build it | Sell as a kit |
|---|---|---|
| Is it assembled before it is sold? | Yes, in batches | No, made or picked at the moment of sale |
| Does it sit on a shelf as a finished thing? | Yes, it has its own stock | No, it holds no stock of its own |
| What does selling one remove? | One finished kit | Its components |
| What does its status mean? | How many are built | How many its components allow |
A workshop’s assembled toolkit is a built kit: you make twenty on Monday and sell them through the week. A café’s breakfast set is sold as a kit: nothing is assembled in advance, and selling one takes a coffee, a pastry, and a cup out of stock.
What a kit costs
A kit’s cost is its components at what they cost now. Take a breakfast set of one coffee at $0.40, one pastry at $1.10, and one cup at $0.05.
| Measure | Calculation | Result |
|---|---|---|
| Component cost | $0.40 + $1.10 + $0.05 | $1.55 |
| Gross profit per set | $4.50 − $1.55 | $2.95 |
| Margin | $2.95 ÷ $4.50 | 65.6% |
Because it is sold as a kit, that $1.55 is worked out fresh every time it is shown, so a rise in the price of pastry appears in the margin immediately. Building instead, you would make twenty sets and each would enter stock at $1.55, folding into the built product’s own average cost exactly as a receipt does; a later price rise then affects the next batch, not the one already on the shelf.
What each action records
Building takes the components out of stock and puts finished kits in, refusing to build more than the parts allow. Each component is taken from where it actually sits, its own location first and then whichever place holds the most, and every part of it is written to the log under one reference.
Selling a kit removes its components the same way, and writes one entry for the kit itself carrying the money: its price, and what its parts cost. The kit’s own entry shows no stock, because it never held any. That is also why the components are not counted as sales of their own: the takings are recorded once, on the kit.
Turning an existing product into a kit sold from components takes whatever it was holding off the books, and records that as a recount to zero so the change is explainable rather than mysterious.
What kits deliberately do not do
Recipes are one level deep: a component cannot itself be a kit. That keeps the arithmetic to a single pass and the recipe list flat, and it avoids turning a stockroom app into a bill-of-materials system. Build a sub-assembly as its own product first if you need two levels.
Reorder never offers to buy a kit, because you do not buy one: you buy or build what it is made of, and the components appear on the reorder list on their own merits. Alerts, the replenish list, and the count sheet all see through a kit to its parts for the same reason. A quantity for a sold-as-kit in a CSV import is left out, and the review step says so before you apply it.