Like the ingredient list on a recipe card, a bill of materials (BOM) lists what's required to complete a project. Though typically used for product manufacturing, BOMs can benefit software developers, engineers, and even marketing and sales teams. In this guide, we’ll cover the different benefits, types, and best practices for writing your bill of materials.
Have you ever rushed through a recipe—maybe skipped a few steps or omitted some ingredients—and then wondered why it didn’t turn out anything like the picture?
Bill of materials (BOMs) are essentially project “recipe” cards—gather your ingredients, follow the steps to a tee, and you’ve got a deliciously successful end result. Just like your favorite cookie recipe, use a BOM to help organize and lay out the requirements needed to complete a project.
A bill of materials (BOM) is an itemized list of materials, components, instructions, and requirements needed to create an end product or deliverable. Though typically used in product development and manufacturing, you can create a BOM for almost any project, from software development to marketing campaigns.
You will typically create your BOM during a project’s planning phase. But this isn’t something you should do alone. Instead, work with key departments, stakeholders, and external vendors or suppliers to ensure you capture every detail.
Present your BOMs in a hierarchical format, with the finished product ranking at the primary level and subassemblies, components, and other requirements listed at lower levels. This centralized document helps everyone get on the same page about the exact requirements and timing needed for the project—regardless of launch type.Create a bill of materials template
An accurate BOM is a single source of truth for producing a finished good or deliverable. Without one, you risk a host of problems—think delays due to lack of inventory, wasted materials, and inconsistent outcomes.
A bill of materials lays out the framework of project requirements for everyone to follow, so teams and suppliers involved in the project are on the same page. This framework helps ensure consistency and simplifies complex processes throughout the project life cycle.
BOMs are essential for calculating the accurate costs of deliverables. If you keep the materials and costs up to date in your BOM, it’ll be easy to track the final cost of the finished product—and whether you’re not on track.
The final cost determines margins, profits, and even taxation levels, so it’s critical that you don’t go over budget. Tracking costs will help ensure your margins remain profitable and prevent scope creep.
A bill of materials give your team a framework to better plan their workflows. By laying out detailed vital functions in your BOM, you may discover process improvements that boost efficiency and profitability—such as the best time to order or restock inventory to prevent downtime or which teams are best suited for which tasks.
With an accurate BOM, you’ll know ahead of time exactly what you need, when you need it, and how much of it to complete your project. This is critical, because missing items or deliverables could force you to halt your project until you have all your requirements in place, leading to deadline extensions and increased operating costs.
In manufacturing, an accurate BOM also improves inventory management since teams will be able to forecast and order the correct quantities of each part of the final product.
You can implement a bill of materials for virtually any project. As a result,there are a variety of project-specific BOMs. If you’re organizing a complex or cross-functional project, you may need multiple BOMs. In this case, each BOM will list the materials and requirements for each component of your project—from design, operations, manufacturing, and more.
Multi-level BOM: A multi-level bill of materials includes multiple levels of hierarchy—with the finished product at the highest level and the individual materials and components below— so your team can visually see the relationships between its parts and components. Breaking your BOM into hierarchies will help your teams understand what pieces are required for each part of the project as they work their way up to the final deliverable.
Modular BOM: Modular BOMs list the materials, documents, parts, and engineering drawings and diagrams you need to complete a subassembly. Use modular BOMs when your deliverables have multiple possible combinations of modules—such as an advertising campaign with various ads showcasing the different benefits of your product or service.
Configurable BOM (CBOM): If you work in an industry that develops highly configurable products, use a CBOM to list all components required to design and manufacture a product to a client’s specific requirements. You can easily mold and shape these documents to reduce the effort needed to maintain product structures. In order to use a CBOM, you must primarily have a modular BOM structure in place.
Engineering BOM (EBOM): An engineering BOM contains the list of items, parts, subassemblies, and assembles needed to create the finished product. Keep in mind a single project can have multiple engineering BOMs, such as one for electrical engineering and one for mechanical engineering.
Software BOM (SBOM): Software BOMs list all the open-source and third-party components present in a codebase. This includes the components’ licenses, versions, and patch statuses to help security teams promptly identify any associated risks. To create high-quality, compliant, and secure code, make sure your SBOM is accurate and up-to-date.
Manufacturing BOM (MBOM): As the name suggests, a manufacturing bill of materials is used for manufacturing projects. An MBOM tracks all the parts and assemblies required to build a complete and shippable product. MBOMs should list every deliverable and milestone—including items used in the assembly process as well as packaging materials, instructions, and guides shipped with the finished product.
Equipment BOM: An equipment BOM lists all replacement spare parts you need to complete your project. This helps maintenance engineers quickly identify, locate, and replace a part. An accurate equipment BOM enables organizations to improve reliability by ensuring the right part is available at the right time.
Whether you’re manufacturing a product or planning your next sales campaign, a BOM can help you acquire exactly what you need to get started.
The data and information included in a BOM will differ from project to project, but in general, most BOMs will include:
Point of contact (POC) information: If a supplier or team member has questions regarding the BOM, include contact information so they can easily get a hold of someone who can help.
BOM levels: In multi-level BOMs, this is the number identifying where each part or requirement fits within the BOM hierarchy. A finished product would be considered BOM level 1.
Required items: List all of the materials, components, or parts needed to complete your project, and make sure to add as many details as possible. This may include product names, part numbers, descriptions, quantity, supplier, unit cost, and total cost for each.
Procurement type: This defines whether the component will be procured in-house or from a supply chain partner or agency. For non-manufacturing BOMs, this is the team responsible for creating each deliverable.
Pictures and URLs: Include diagrams, images, or links if applicable.
Priority: In any project, there are required deliverables and nice-to-haves. Track which is which to protect your project from scope creep. For example, you may want to make note of which components have the longest lead times or highest monetary value so your team knows to pay special attention to them.
Potential alternatives: If there’s flexibility regarding a component or part, include potential alternatives in case the original isn’t available.
Revision level: Listing the revision level for your BOM—or a way to identify how many times your BOM has been reviewed and revised— will help stakeholders quickly understand the changes these requirements have undergone. This is typically a simple R1, R2, R3, etc listed at the top of the BOM.
You can create a bill of materials as a static document or a dynamic tool.
Download our static bill of materials template to effectively manage the fine details and components of your next project.
Alternatively, create a dynamic project that you can use to ensure your entire team is aware of what’s required to complete an accurate, high-quality finished product.Create a bill of materials template
A bill of materials is an extensive document that will require significant time and attention. An effective BOM can improve team communication, collaboration, workflows, and inventory management. Here are a few general best practices to follow to ensure your BOM is accurate and effective.
Before creating your BOM, identify what should be included and customize it to the unique requirements of your project. Think of how different industries might use a BOM.
If you’re building a bicycle, you’d probably include part numbers, quantities, and units of measurement. However, these details wouldn’t apply to a UX BOM for a homepage redesign.
You might wonder whether a little detail like glue or fasteners is significant enough to be listed in your BOM. Think about it this way—if you don’t include the requirement in your BOM, it won’t be in the final product.
Small things can make a big difference in the accuracy of your BOM. Take the time to list as much helpful information as possible to ensure your document is thorough and concise. The more detail, the better.
Not everyone involved in a project needs to edit the document. Formalize the process of who has what permissions in order to reduce confusion and human errors. Allow editing privileges only where necessary—you’ll find most people within your organization only need read-only access anyway.
A BOM is a dynamic document, meaning you’ll need to make changes and updates to it throughout the project lifecycle. However, too many changes and a lack of oversight can lead to inaccuracies and a low-quality end result.
Develop a system to monitor any changes made to the BOM. This way, you can identify and correct errors before they impact the finished product.Read: What is a change control process and how do you use it?
There will likely be multiple departments and people creating BOMs for each phase of the project, which is why we recommend using a template that is compatible with the group.
This way, you can implement a consistent ordering process, standardize communication, and still have the flexibility to customize the template to fit your needs.
No matter your goals, a properly organized BOM lays the foundation for your project's success. To get started, download our template and customize it to best fit your project needs.
Include all parts, components, requirements, and any other resources you think your team would find helpful—and remember, it’s always better to have more detail than not enough.Create a bill of materials template