A Guide to the Bill of Materials (BOM) in the Fashion Industry

Preparation for a large holiday meal always begins with a shopping list. Skip that step and you might buy wrong ingredients or forget key items.

The same is true in the fashion industry, with a list called a bill of materials (BOM). Before sourcing begins or samples are cut, teams need a single shopping list of every component that goes into a garment: what they are, how many are needed, and the vendors supplying them. The BOM helps prevent delays that arise from missing materials, mitigates the risk of overordering, and can even assist in sourcing and compliance. Seemingly tactical, a BOM is actually a strategic element in apparel industry cost control, inventory management, and production planning.

What Is a Bill of Materials (BOM)?

A BOM is a comprehensive, standardized list of all the items required to manufacture a finished product, including the packaging materials for shipping the product to customers.

Treated as a living document, each BOM is a core page within a tech pack—the technical document that includes detailed instructions and specifications for accurate production. In the fashion business, the BOM covers the raw materials, trims, packaging, and anything else required to produce a garment that’s ready for sale.

Key Takeaways

• A fashion BOM lists every material, including its quantity, cost, and other details, needed to make a garment.
• Accurate BOMs result in less waste, more accurate costing, and better decision-making.
• Adopting solid best practices can sharpen BOM accuracy and decrease production delays.
• ERP or MRP software with BOM capabilities automates handoffs, tracks revisions, and provides SKU-level transparency.

Bill of Materials in the Fashion Industry Explained

At first glance, a fashion BOM seems to be little more than a list of materials required to produce a garment. In reality, it also supports the sourcing process, breaks down costs, and equips production teams to prepare garments for finished goods inventory. Fashion BOMs are useful as both planning and operational tools. On the planning side, for example, a BOM identifies opportunities to buy in bulk, which lowers costs per unit while maintaining quality. On the operational side, a BOM serves as a bridge between apparel design and production, detailing each component down to color combinations (aka colorways), units of measure, and supplier codes. The BOM also informs the sequence of construction (SOC), helping patternmakers and sample rooms plan the order of operations and standardize production. Simply put, a BOM is a planning tool, communication guide, and costing reference all in one.

Early-stage BOMs will often include “TBD” placeholders until businesses have finalized their designs. Once styles are defined, details like fabric types, colorways, trims, closures, packaging, quantities, measurements, supplier information, waste estimates, and costs come together to aid sourcing decisions and standardize production. Unsurprisingly, success often rides on the accuracy of the BOM, because even minor errors or oversights can delay production. By automating the process, apparel manufacturers can create a BOM for every style-color-size SKU and update it within a centralized database as changes occur. Teams can easily track changes, with automated handoffs from product development to manufacturing to inventory control. The result is greater speed, accuracy, and margins at scale.

BOM Structures

The following detail the two types of BOMs, depending on the complexity of the garment:

• Single-level BOM: This is a flat list of every material and component needed to make the final garment. A single-level BOM is best for the early development stage of a garment or for simple styles. It is also the easiest to create, though it lacks flexibility to track subcomponents or to group materials by use.
• Multilevel BOM: This hierarchical structure segments the garment into functional categories (for example, shell, lining, trims, packaging), each with its own list of materials. This structure aids costing and allows for high-level automation of purchasing and finished inventory management—a plus when dealing with complex designs or designs with several variations.

Why Does an Accurate BOM Matter for Apparel Companies?

The value of a well-documented BOM can be quantified in many ways, such as reduced manufacturing costs and less fabric waste. It also offers benefits outside of production. Some primary advantages of accurate BOMs include the following:

• Lower production costs: BOMs delineate raw materials, units of measure (if applicable), and approved suppliers. By documenting the details, companies are less likely to waste budget on overstocking, holding costs, and costly rush orders. They also make costing sheets more accurate, giving finance teams reliable data for calculating total manufacturing cost.
• Decreased fabric waste: BOMs list all required materials and their exact quantities, boosting order accuracy. This precision helps companies manage fabric purchases efficiently and decrease overall costs.
• Fewer errors: A BOM helps minimize order mistakes that result in inaccurate quantities, which can slow production and ultimately waste money. It’s also useful for quality-control purposes, as any material or product discrepancies can be traced back to the supplier listed in the BOM.
• Centralized data: BOMs can be used for sourcing, costing, and production purposes, which means the same information is available to everyone. This enhances inventory management and control; it also simplifies compliance, ethical sourcing, and sustainability reporting.
• Improved decision-making and planning: With access to all material and costing breakdowns, managers can model different scenarios to impact production costs and schedule, such as changing fabric or order sizes. Strong materials management practices rely on BOM data so that the right materials are available at the right time and place.
• Increased production speed: Organized BOMs lessen the back-and-forth between design and manufacturing. Factories have instructions up front to speed up sampling rounds and better meet production schedules. This speeds time to market, which is especially beneficial in fast-fashion supply chains.
• Sales, marketing, and customer service support: Sales and marketing teams can use BOM information to set pricing, create marketing campaigns, forecast sales, and showcase product features. Customer service teams can also turn to BOMs for troubleshooting product issues.

What Is Included in a Fashion BOM?

A fashion BOM should capture all the necessary details to produce a garment. Standard elements include the following:

1. BOM category: Organizes components by type, such as shell fabric, lining, trims, and packaging.
2. Fabric details: Describes fiber content, type of weave or knit, weight, width, and finish. Fabric details influence the cost of raw materials and, ultimately, total manufacturing costs.
3. Color or pattern: Specifies shade, print, or Pantone color code so that the product design can be replicated across different production runs. Each colorway should have its own BOM to avoid inconsistencies at the SKU level.
4. Accessories, embellishments, or trims: Includes closures, buttons, zippers, labels, or embroidery, along with exact measurements and finishes.
5. Packaging information: Refers to hangtags, polybags, tissue, cartons, and other packaging materials.
6. Quantity: States how much of each component is required per garment.
7. Unit of measurement (UOM): Standardizes how consumption is documented, whether by meters, yards, pieces, or sets. UOM information also supports inventory and warehouse management, letting teams plan how to allocate space.
8. Measurements: Provides dimensions for materials, such as zipper or fabric length. These figures refine cost breakdowns and sourcing calculations.
9. Description: Consists of a short identifier, often with a supplier code, distinguishing one material from another.
10. Wastage: Quantifies a buffer percentage to account for fabric lost during cutting or due to defects. It helps prevent shortages that interrupt production.
11. Total number: Indicates the total quantity of each material needed for the whole production run.
12. Unit cost: Specifies price per yard, piece, or other UOM, which helps maintain accurate costing sheets.
13. Total cost: The overall cost to produce a garment, as calculated by multiplying the unit cost by the required quantity (including wastage) for each item, then adding those totals.
14. Supplier information: Includes vendor names, lead times, and minimum order quantities.
15. Approval details: Denotes approval status, date, and approver, creating accountability and signaling to production managers which components are ready to move forward.
16. Notes: Provides a place for special instructions, approved substitutes, requirements for compliance, or other important details that don’t fit neatly in the BOM.

How Are BOMs Used in the Fashion Industry?

A BOM guides nearly every step of apparel production. Consider the production of a denim jacket. Once the garment’s design is complete, the designer initiates the BOM, which includes denim for the outer shell, fabric for the lining, thread, trim, hardware, and packaging material. Next, the product development team uses the BOM to establish order quantities and to review the costing sheet, which is the basis of effective pricing and budgeting. For example, if a style requires buttons, zippers, or trims, the BOM allows planners to account for the standard quantities plus a specific percentage extra to cover production loss or quality issues. The same principle applies to fabric, thread, labels, or other materials.

From there, sourcing and supply chain professionals use the BOM to confirm suppliers, issue requests for quotes, and assign lead times so materials arrive at the right time for each stage of the production schedule. As the jacket advances to the cutting, sewing, and finishing stages, factories use the BOM to verify the SOC, allocate resources, compare actual and planned consumption, and document variances. Merchandisers use it to verify breakdowns of costs and totals, which justifies final product pricing. Quality teams can check finished items against the BOM to confirm correct manufacturing.

Example Fashion Bill of Materials

Let’s examine the BOM for the denim jacket described above to illustrate how the categories all come together.

Once a BOM is created for a style, additional colorways are typically generated by duplicating the original and updating only the components that change, such as fabric color codes and button finishes.

Tips for Creating a Good Fashion BOM

Even the most thoughtfully designed garment can incur costly problems if its BOM contains errors or ambiguities. Adopting the following best practices can enhance accuracy, limit production delays, and maintain cost transparency:

1. Standardize BOM entries and format:

   Consistency is key to managing an apparel BOM used and accessed by multiple teams. Establish naming conventions to limit confusion. Use a standard format to save time during product development, as this makes BOMs easier to review and share across departments.

2. Communicate clearly and consistently:

   BOM descriptions must be explicit, noting specifics like size, type, and color code. Clarity prevents sourcing errors and helps when matching the final product to the approved design.

3. Keep BOMs updated:

   Every design revision, costing sheet update, or supplier change should be recorded promptly. Outdated details can waste time, increase total cost, and disrupt inventory management. Regular BOM reviews are advised to maintain version control.

4. Identify automation opportunities:

   Automation can simplify BOM management by duplicating base templates, generating new versions for size or color variations, and updating variables, such as material specs or costs. It can also calculate totals, apply wastage factors, and flag reorder needs. These efficiencies reduce manual rework, improve accuracy, and let teams focus on higher-value tasks.

5. Make sure costs are clearly listed:

   Every BOM entry should include the unit and total cost for the production run. These figures become the foundation for sample costing analyses and pricing decisions. Cost transparency can also reveal areas to lower manufacturing costs without compromising quality.

6. Ditch writing manual BOMs:

   Traditional spreadsheet BOMs are susceptible to errors, version conflicts, and missing data. Better options include a material requirements planning (MRP) or ERP system, which unites product development, sourcing, and inventory control data in a single platform. Not only do teams have access to the same real-time data, but built-in version control, audit trail creation, and role-based editing also prevent mistakes, maintain data integrity, and enhance collaboration.

How Modern ERP Software Optimizes Production Costs

NetSuite Apparel ERP gives fashion companies accurate, up-to-date BOMs by connecting product development, sourcing, and inventory management within a unified cloud solution. The system lets businesses create detailed multilevel BOMs that specify all materials, components, and subassemblies required. It also allows for the auto-population of new BOMs using templates or previous styles, reducing manual data entry and speeding product development. All stakeholders can access and update material costs, procurement schedules, and production details, eliminating the confusion of juggling multiple spreadsheets. Built-in financial tools link cost details directly to margin analysis, while demand planning and supply chain modules align production closely with customer demand, all for greater control over inventory and profit.

When fashion BOMs are updated throughout a garment’s lifecycle, apparel companies can reduce waste, prevent duplicate orders, and avoid missed deadlines—issues that can silently chip away at margins. Accurate, real-time data allows for faster, more informed decisions in an industry in which even a week’s delay can result in lost sales. Beyond efficiency, a comprehensive and highly automated BOM approach supports better communication and collaboration among departments and reduces the misunderstandings and mistakes that occur when teams work in silos.

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Fashion BOM FAQs

What is a BOM in the garment industry?

A bill of materials (BOM) is a master list of everything needed to create a specific garment, such as the materials, trim, and other components, as well as labels and packaging. It outlines the quantity, unit of measure, supplier, and cost for each item.

What is the format for a BOM?

No standard format exists for a bill of materials (BOM), although most fashion BOMs are presented in a table that groups materials into categories, such as shell fabric, lining, closures, and packaging. Each row includes details like color, size, unit cost, total quantity, supplier, codes, and other relevant notes.

Who prepares a BOM?

Typically, a technical designer or product developer will create a bill of materials (BOM) before proceeding with sample production. After that, the BOM is updated collaboratively during product development, with sourcing, costing, and production information fleshing them out along the way until the garment design is finalized.