This page explains how to build a bill of materials that a factory or buyer can actually check, for anyone who reads or approves a tech pack before an order runs: a buyer, a merchandiser, a factory costing team, or a new entrant to the trade. This lesson mainly teaches money: whether the cost figures written into a tech pack actually add up to the price everyone has agreed to.
Lesson 5.1 already showed what a tech pack is: the document set a factory needs to make a garment. One of its sections is the bill of materials, the list of every material and cost component, each with its own cost, that together build up to the total FOB price. A new entrant can assume that once a bill of materials states a total price, the job is done. It is not. A stated total can be correct-looking while the components listed underneath it secretly fail to add up to it.
Without checking this, a buyer can approve a tech pack whose bill of materials looks complete, and only discover the error later, once someone tries to reconcile the components against the total.
You need: lesson 5.1 (What a tech pack is) is useful background, since this lesson builds one of its sections in detail, but it is not required to follow this lesson.
By the end of this lesson you can:
Not covered here: what a tech pack is and why every order needs one (lesson 5.1); construction detail and measurement specs (lesson 5.3); grading rules, labelling and packing (lesson 5.4); assembling a complete tech pack (lesson 5.5).
| Term | Meaning |
|---|---|
| Bill of materials | The list of every material and cost component in a garment, with its cost, used to build up the FOB price. |
| Cost component | One part of a garment's total price: fabric, trims, making, overhead, or profit. |
| FOB price | The price the factory charges for the garment, delivered on board the ship at its own port. |
| Lump-sum bill of materials | A bill of materials that states only a total figure, with no separate component costs shown underneath it. |
A bill of materials lists every material and cost component in a garment, each with its own cost, that together build up to the total FOB price. Order A's own fixed breakdown, already fixed for this academy, is: fabric USD 1.15, trims USD 0.20, making USD 1.10, overhead USD 0.49, and profit USD 0.26, summing to an FOB price of USD 3.20. A complete bill of materials lists each of these five components separately, never as one lump "cost" figure, because a factory or a buyer reviewing it needs to see where the money goes, not just the total it adds up to.
Listing components separately matters for a second reason beyond checking the arithmetic: it lets either side negotiate one component at a time. A buyer who wants a lower FOB price can ask which component to target, fabric, trims, making, overhead, or profit, only if each one has its own visible figure. A bill of materials that hides all five inside one number gives neither side anything to negotiate against, and gives a reviewer nothing to check the total's own arithmetic against either.
A bill of materials does not always arrive in the same, complete shape. Some versions look finished but hide a problem underneath the total.
| What can differ | The shapes you meet | Why it matters |
|---|---|---|
| Complete bill of materials | Every component listed separately: fabric, trims, making, overhead, profit, summing to the correct FOB total. | This is the standard a bill of materials is checked against before it is used for quoting or approval. |
| Lump-sum bill of materials (incomplete) | Only a total FOB figure given, with no component breakdown underneath it. | Cannot be checked or adjusted component by component, since the breakdown that would allow that is not there. |
| Bill of materials with a math error | Components listed separately, but they do not sum to the stated total. | A red flag requiring correction before the document is used, even though it looks complete at a glance. |
| Order A's own case | Its own fixed five-component breakdown, fabric 1.15, trims 0.20, making 1.10, overhead 0.49, profit 0.26, summing correctly to 3.20. | The real, complete worked example this lesson builds from, and the standard the other two shapes are compared against. |
Northline Apparel's buyer is reviewing Order A's tech pack ahead of a bulk production approval. Before signing off, the buyer checks that the bill of materials' component figures actually sum to the stated FOB total, rather than approving the tech pack on the strength of the total alone. This is an export order, Make to Order, run for Northline Apparel by Delta Garments: nothing moves into bulk production until the buyer has approved the complete tech pack, and the bill of materials is one of the sections that approval depends on.
Order A's own fixed figures, already fixed for this academy, are fabric 1.15, trims 0.20, making 1.10, overhead 0.49, and profit 0.26. Adding them one component at a time shows they sum correctly to the stated FOB total.
Every step above uses one component at a time, so a reviewer can see exactly where the running total comes from, rather than trusting a single stated figure of USD 3.20 without seeing how it was built.
The methodA common mistake is accepting a bill of materials because its final FOB figure "looks right," without actually adding up the component figures underneath it. A bill of materials can state a correct-looking total while its listed components secretly do not sum to it, an error that only shows up once someone actually checks the arithmetic. A reviewer who glances only at the bottom line, and never runs the sum-and-verify check, can approve a document that already contains a hidden mistake.
This trap is easy to fall into precisely because the stated total is usually the number everyone already recognizes. A reviewer who has seen Order A's FOB price of 3.20 many times before can see it stated again on a new bill of materials and treat that alone as confirmation, without noticing that the five figures listed above it no longer add up to that same number. The stated total looking familiar is not the same as the stated total being correct for this particular document.
A bill of materials lists every material and cost component in a garment, each with its own cost, adding up to the total FOB price. It should never show just one total figure with no breakdown; that is a lump-sum bill of materials, and it cannot be checked or adjusted component by component. Order A's own fixed breakdown is fabric 1.15, trims 0.20, making 1.10, overhead 0.49 and profit 0.26, which sum correctly to an FOB price of 3.20. The check anyone can run is simple: list each component, add them together, and compare the running total against the bill of materials' own stated total. If the two do not match, the bill of materials contains an error that has to be found and corrected before it is used for quoting or approval. A total that "looks right" is not proof the components underneath it actually add up to it; only running the sum proves that.
Northline Apparel's buyer is checking a submitted bill of materials for Order A's T-shirt, ahead of approving Delta Garments for bulk production. The facts in front of the buyer:
The document the buyer reads, the submitted bill of materials, exactly as quoted:
Is this bill of materials correct? Decide before you open the answer.
Adding the five listed components, one at a time, the same way the worked number above did:
No. The listed components sum to 3.26, not the stated 3.20.
Two facts, together, decide this. First, Order A's own fixed breakdown fixes overhead at 0.49, not 0.55, so the submitted overhead figure disagrees with the academy's own fixed number. Second, this lesson's own trap: the stated total of 3.20 "looks right," because it matches what everyone already expects Order A's FOB price to be, but it does not match what the five listed components in this document actually add up to.
Either the overhead figure or the stated total contains an error, and the buyer should not approve this bill of materials for quoting or bulk production until the discrepancy is found and corrected. The most likely correction, given Order A's own fixed breakdown, is that the overhead figure should read 0.49, not 0.55.
This lesson's cost is framed against the concrete discrepancy found in block 08: the submitted overhead figure of 0.55 against Order A's own fixed overhead of 0.49, a difference of USD 0.06 per piece.
Multiplied across Order A's full order of 15,000 pieces, an unchecked 0.06 discrepancy on a single component becomes USD 900 across the whole order. This is framed qualitatively rather than as a fixed academy figure, since the size of any real discrepancy varies by order; the point this lesson's sum-and-verify method is designed to prevent is exactly this kind of unchecked arithmetic error, which can under-quote or over-quote an entire order by a meaningful amount before anyone notices.
Copy this table into the tech pack template pack's Tech Pack Sections sheet, using Order A's own fixed breakdown as the reference row. Fill the "Complete" column only once the components have actually been summed and checked against the stated total.
| Cost component | Figure (USD) | Source | Checked against stated total |
|---|---|---|---|
| Fabric | 1.15 | Order A's own fixed breakdown | |
| Trims | 0.20 | Order A's own fixed breakdown | |
| Making | 1.10 | Order A's own fixed breakdown | |
| Overhead | 0.49 | Order A's own fixed breakdown | |
| Profit | 0.26 | Order A's own fixed breakdown | |
| Stated FOB total | 3.20 | Sum of the five rows above |
Download the full working sheet, with the example row already filled in, from the link on this course's page.
1. What five components make up Order A's own fixed FOB breakdown?
2. Why is a lump-sum bill of materials, just a total FOB figure with no components, incomplete?
3. A submitted bill of materials lists fabric 1.15, trims 0.20, making 1.10, overhead 0.55, profit 0.26, with a stated total of 3.20. The components actually sum to 3.26. What should happen?
| EN | AR | FR | TR | Meaning |
|---|---|---|---|---|
| Bill of materials | قائمة المواد | Nomenclature | Malzeme listesi | The list of every material and cost component in a garment, with its cost, used to build up the FOB price. |
| Cost component | عنصر التكلفة | Élément de coût | Maliyet bileşeni | One part of a garment's total price: fabric, trims, making, overhead, or profit. |
| FOB price | سعر التسليم على ظهر السفينة | Prix FOB | FOB fiyatı | The price the factory charges for the garment, delivered on board the ship at its own port. |
| Lump-sum bill of materials | قائمة مواد بمبلغ إجمالي واحد | Nomenclature forfaitaire | Toplam tutarlı malzeme listesi | A bill of materials that states only a total figure, with no separate component costs shown underneath it. |
You now know how to build and check a bill of materials against a stated FOB total. The next lesson adds two more tech pack sections to Order A's own file: construction detail and the measurement spec, so a factory can also cut and sew the garment correctly, not only cost it correctly. Back to the course map