Menu Close

The Importance of a Bill of Materials

A bill of materials (BOM) is a central record that can be used to help plan what to purchase, estimate costs and aid in planning and controlling inventory. It can also reduce production delays and waste.

It is also useful for coordinating design, product development and manufacturing teams to cohesively collaborate. It can be a single or multi-level document.


The cost of a bill of materials (BOM) is a key part of your manufacturing operations. This information helps you make informed decisions about purchasing, production schedules and other operational efficiencies. For example, if you know that it is more costly to make a product internally than to outsource its assembly, you can make appropriate trade-offs to maximize profit. This knowledge also helps you avoid production delays, reducing the risk of wasted inventory and other unnecessary costs.

A BOM is a list of the assemblies, components and raw materials needed to make a product. It includes the item name, description, quantity and unit price of each component. It also provides the guidelines necessary for assembling and using these items. The information can be used to create a material requirements plan, an assembly schedule or a manufacturing process flow chart. BOMs are used in a variety of industries, from job shops to heavy equipment manufacturers.

When creating a BOM, be sure to use consistent unit measurements. This will help you keep track of inventory and ensure that your assembly instructions are accurate. For example, if you are producing soap that requires a specific amount of liquid, your units should be ounces or some other standard measure. Then, when you order ingredients, you will be able to get the correct quantity that you need to make your product.

Another important feature of a BOM is the reference designator, which shows how each component fits into the final product. This is particularly important for electronic products that incorporate printed circuit board assemblies – PCBAs. This allows you to clearly identify the location of each component and the relationship between it and other components in your design. This will help you ensure that each component is placed correctly on the finished product, which minimizes errors and rework.

A multi level bom is a more complex version of a single-level bom that includes sub-assemblies and component parts. This type of bom is often indented, showing the relationship between the parent item and its child items. Multi-level boms can be time consuming to update. They also require a lot of attention to detail.


A bill of materials is an essential tool for manufacturers. It provides a list of all the components required to create a finished product and identifies the relationships between them. This information can then be used to determine the cost of production. It can also help reduce issues like incorrect ordering of parts, which can result in costly delays and lost productivity.

The quantity of each component can be specified in either a decimal or a number format. It is recommended that the unit of measure be consistent with your production process. This can make it easier to purchase raw materials in the correct quantities and helps ensure that the right amount of material is being used on the shop floor. For example, a BOM for soap may use units of measurement such as “ounces” while a BOM for a computer might use units such as “inches.”

BOMs can be categorized into two types: single-level and multi-level. A single-level BOM is the most basic form, and it consists of one row for each item in the assembly. It also includes a description of each item and its specifications. A multi-level BOM, on the other hand, shows the relationship between different assemblies and subassemblies, as well as the quantities needed for each.

Regardless of the type of BOM, it’s important to maintain accurate and up-to-date information. This will ensure that all products are made correctly and efficiently. It will also prevent errors and improve communication with suppliers.

A BOM is also useful when negotiating pricing and delivery lead times with suppliers. The BOM will give suppliers an idea of how much the project will cost, which will allow them to provide you with pricing and delivery estimates more quickly. In addition, a BOM can be used to track changes to existing projects or planned manufacturing orders.

A BOM can be created in many formats, including spreadsheets and electronic documents. However, these documents can be difficult to share and manage. They are often large, making them hard to send to other users. Additionally, they can be difficult to edit. This can cause problems if you need to update a spreadsheet or document in real time.


A bill of materials is a comprehensive list of raw components, parts, assemblies, and other items used to make a product. It also includes the quantity and cost of these items. It provides important information to organizations, including their suppliers, which can help them save money by avoiding costly mistakes and eliminating waste.

BOMs can be created in several formats, ranging from simple spreadsheets to complex enterprise resource planning (ERP) and manufacturing execution system software. They can be organized in many ways, such as by product type or assembly sequence. They may also be sorted by location, supplier, or customer. This allows you to find the right information quickly and easily.

In addition to providing important production and supply chain information, a well-organized and up-to-date BOM can help improve decision-making. It can also increase efficiency and productivity. This is because it allows companies to move products from design into production faster, which can help them capture customers. It can also help reduce production delays and inventory overages and shortages. A BOM can also reduce the time it takes to identify a problem and work quickly to correct it.

The description of a BOM should be clear and concise. The purpose is to make it easy for anyone to understand the meaning of each part or assembly in the bill of materials. This is especially important when using a multi-level BOM. This document is usually arranged in a hierarchical manner, with the finished product at the top of the list and the individual parts or components below it. The description should include the part name, its function, and any additional notes.

There are two main types of bills of material: a manufacturing bill of materials (mBOM) and an engineering bill of materials (EBoM). A mBOM is designed to describe the parts or assemblies needed to build a finished product, while an EBoM is used to define the product in its development stage. EBoMs are often used in conjunction with configurator software.

A mBOM is the most widely used type of BOM in a manufacturing company. It contains a list of the components and parts required to build a product and the instructions for assembling them. It also includes the quantities of each component or part, and is usually presented in a hierarchical format with the finished product at the top, then the sub-assemblies, subcomponents, and components below it.


A bill of materials is a comprehensive list of raw materials, subassemblies, components and parts that are required to construct or manufacture a product. It also includes the quantity of each item needed to make the end product. It is also known as a product structure, assembly component list or production recipe (in process manufacturing industries). The BOM serves as the communication medium of the manufacturing team with the stores team.

There are different types of bills of materials: engineering and manufacturing. A engineering bill of materials is used in the design phase and is based on a computer-aided design or CAD drawing. It is often created as part of the product lifecycle management process. A configurable bill of material is a version of a modular BOM that is used by industries with multiple options and highly customizable products.

In addition to listing raw materials, assemblies and components, the bill of materials must include the method of procurement, and any other information that is important to the manufacturer. For example, the manufacturer may require that lasagna meat is made from only 100% US beef.

BOMs help to avoid overage and shortages by ensuring that the correct quantities of materials are available to meet production schedules. They can also be used to improve inventory control and reduce waste by identifying the items that are not needed. In addition, the centralized source of information helps to ensure that the assembly process is accurate and efficient.

Modular BOMs are arranged in hierarchical order and contain a list of raw materials, components and sub-assemblies for each level of the product. The top-most level is the finished product, followed by the components and then the raw materials. Each of these is then further broken down into sub-assemblies, which are listed in a parent-child relationship from left to right and appear indented.

A template is a good way to create a bill of materials for your business. It can help you to standardize your communication procedures with all stakeholders, from internal departments and industry experts to suppliers and vendors. A well-designed BOM template can also help you to project your inventory needs accurately, which can reduce waste and lower your operating costs.