What is a bill of materials (BOM)? Create a bill of materials

A bill of materials (BOM) is somehow equivalent to your grocery list. Imagine that you have decided to bake a cake. The first thing you do is to make a list of all the items required to bake the cake, for instance, flour, baking powder, vanilla essence etc. You also list out the quantities of the items required to bake the cake.

Aditya Kumar
Jul 23, 2024    |     7 mins read

This list that you just made listing all the materials required, the quantities in which you need them, and sometimes even the cost, can be compared to the bill of materials (BOM). In simple words, bill of materials (BOM) can be thought of as a list with all items required and in relative quantities to build a product. 

What is a bill of materials (BOM)?

A bill of materials (BOM) can be defined as a detailed and complete inventory/list of all the parts, raw materials, subassemblies, subcomponents required in the manufacturing process of a product. Further, it also lists out the quantities in which these raw materials are needed to build the product. The costs of the components and their description can also be found in the bill of materials. 

In addition, BOM can also be regarded as a guide book or a user manual. A user manual indicates how to use the materials to build the desired product. Similarly, the bill of materials (BOM) consists of instructions on how to use the materials to build the product.

What are the uses of bill of materials (BOM)?

A bill of materials is essentially useful in the manufacturing unit as it simplifies the process. Following are the different uses of BOM:-

  • A bill of materials increases the efficiency of the manufacturing process.

  • Accurate manufacturing can be achieved using BOM.

  • Simplified process.

  • Using a bill of materials (BOM), a manufacturing unit can be informed of all the items required to build a product. 

  • BOM eliminates the risk of last minute hassle as the organisation already knows what all they need, and in what quantities.

  • A BOM also helps in estimating the costs of materials.

  • A BOM allows the industry or organisation to keep a check on their budget.

  • Not making use of a bill of materials (BOM) will only be to a disadvantage as it would increase added costs and time

  • A BOM also helps to reduce waste

  • A bill of materials is also useful in the sense that it allows the companies to be confident and provides a sense of  that the final product would meet their expectations.

What are the different types of bill of materials (BOM)?

A bill of materials comes in varied types and forms. One can choose from the multiverse of options, depending on the requirements of your business model. Different types of bill of rights are listed below-

  • Engineering bill of materials (EBOM)-

An engineering bill of materials (EBOM) lists out the designs and parts provided by the engineering department. The engineering BOM represents the structural part and also showcases a theoretical drawing. The design is created using CAD (computer aided design) by the engineers. A product can consist of one of more than one engineering bill of materials, depending on the situation

  • Manufacturing bill of materials (MBOM)-

A manufacturing bill of materials (MBOM) is a detailed and informative list which includes all the raw materials, inventory, subassemblies etc that would be required to produce the product. This product would be absolutely final in nature which would be immediately ready to be shipped. The BOM also indicates the correlation between different components of the product. It also mentions whether any component requires processing or manipulation beforehand. MBOM is made readily available to all the businesses that are involved in the building of the product. 

  • Sales bill of materials (SBOM)-

When the product is about to enter the sales stage, SBOM is made ready and consists of the details of the products. 

  • Configurable bill of materials (CBOM)-

The businesses that use highly configurable products use the CBOM. The CBOM helps in maintaining the structure of the products, thus reducing the workload. 

The configurator software is involved in the working of configurable bills of materials.

Who makes the bill of materials (BOM)?

The bill of materials (BOM) provides a wide range of information. The information is varied and hails from different departments of the company. The engineering department, design department, manufacturing department, sales department, all chip information in order to make the bill of materials. 

Who uses the bill of materials (BOM)

In the above sections we saw different types of bill of materials namely engineering bill of materials, sales bills of materials etc. The different bill of materials is hence used by different departments. The EBOM is used by engineering, the MBOM is used by manufacturing and so on.

Components of the bill of materials (BOM)

  • Part Name- The name of the parts required to build a product is mentioned in the bill of materials. This facilitates the manufacturers to gain more information on the parts.

  • Part Number- A part number is a unique number which indicates some information about the part. The part number makes it easy for the manufacturer to gain some first hand information about the part at a quick glance. 

  • Levels- Levels of the parts are indicated on the bill of materials. The levels indicate the importance of the parts.

  • Part Phase- Part phase indicates its age. For instance, whether the part is new or the revised version.

  • Manufacturer name- The manufacturer's name is listed in the bill of materials (BOM) which further helps in gaining more information.

  • Alternate parts- Names of alternate parts are usually mentioned in the bill of materials, which helps the manufacturers know which item to look for in replacement or unavailability of a given part.

  • Description- A detailed description of each part is given in the bill of materials. For instance, the length of the part, the colour of the part, or the dimensions etc are mentioned in the bill of materials.

  • Quantity- The number of items required to build the product is mentioned in the bill of materials (BOM), along with its description.

  • Notes- Some personalised notes or comments are written in order to provide further clarifications.

Advantages of bill of materials (BOM)

  • Efficiency- A BOM is efficient for the manufacturing unit. It helps provide accuracy in the building of a product.

  • Readily available- A bill of materials is a clear and comprehensible list of the inventory needed in order to build a product. Since it will be available with the manufacturer, it will help remind the needs. 

  • Less Waste- Less waste will be generated using the BOM as one would be aware of what is required and what is not. Thus enabling the manufacturer to gather only the required items or raw materials, reducing the generation of waste.

  • Budget Control- Unnecessary purchase of items or inventory which is not required in the process of building a product would be avoided if the manufacturer has a bill of materials. 

Things to keep in mind before creating a bill of materials (BOM)

  1. Who will be using the BOM created by you?

 It is necessary to know who will use the BOM because you might not physically meet the person who is going to use the BOM. Hence, you need to make sure every piece of information you wish to convey is clear and concise and in detail.

2. How to increase clarity of the BOM? 

If you are attaching CAD drawings in the bill of materials, make sure to link the drawings with the particular components in order to avoid confusion.

How to create a bill of materials (BOM)

  1. Define the product

An exact description or definition of the product is utmost necessary because even a slight variation may result in the requirement of different items. 

2. Make a check list of the items

A list of the raw materials and inventory required to build the product must be made. It would also include the subassemblies. 

3. Give unique part numbers

Identifying each part as a unique set of digits will help provide clarity and accuracy. It is also an efficient way to keep a track of the inventory. 

4.List the Quantity

Identifying the quantity of the raw materials required is important. This would help minimise waste. 

5. Calculate costs

At last, you must calculate the costs involved. You must calculate costs of each component in accordance with their quantity. This will help generate an overall idea of the entire cost of the product.

6. Keeping up with the updates

You must keep updating the bill of materials (BOM) as per needs.

7. Keep a copy of the BOM on spreadsheet or software

Making use of any software or spreadsheet in order to store your BOM will help you access it anytime. 


As we can see, a bill of materials (BOM) is a. lifesaver as it comes with so many advantages. It helps to carry the work in an organised and effective manner. Though creating a bill of materials makes it seem a hassle, an organisation or business can be of great benefits using a BOM. 


Q) Can a bill of materials be created on excel?

A) Yes, creating a bill of materials on excel will be of great advantages.

Q) What are the different types of bill of materials?

A) Engineering bill of materials, manufacturing bill of materials, sales bill of materials, configurable bill of materials etc.