For manufacturers—no matter the product—boosting the efficiency, productivity, and accuracy of their production processes is very important, and rightly so.
Imagine creating a building structure from the foundation without a blueprint or plan. There would be a lot of confusion, leading to a waste of time and precious resources, right?
A Bill of Materials, in its very basic form, serves as a blueprint for production and is a necessary addition to your planning process. That said, let us understand the Bill of Materials meaning first, and then all the components included in a typical BOM.
What is Bill of Materials (BOM)?
A Bill of Materials (BOM) is an official product-specific document that contains all the information about the raw materials, components, and blueprints associated with its production or assembly. A BOM will help you navigate all the processes from start to finish smoothly, whether you are producing a drink or assembling an electronic device at your facility.
BOM is crucial in manufacturing as a centralised document that dictates how to produce or put together a product and removes any communication issues or gaps between departments. As a result, it is commonly used in electronics, automotive, manufacturing and aerospace industries.
8 Primary Components of a Bill of Materials
Most Bill of Materials templates follow a standardised structure with the finished product at the top, branching into sub-assemblies and their individual components.
Further branching will depend on the hierarchical structure of all the components in your product, creating a pyramid-like structure with the finished product at the very apex.
The overall structure of the Bill of Materials may also vary based on whether you represent it as a single-level or multi-level BOM (which we will discuss in a bit). For now, let us look at the primary components included in a typical BOM, with an example for better understanding:
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Product Name
If your company manufactures multiple products with different kinds of parts and components, chances are you will be working with multiple BOMs at the same time. Mentioning the Product Name right at the top of a BOM prevents confusion and identifies a specific assembly or product.
Example: A Black Formal Shirt
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Part Name
The purpose of a BOM, after all, is to have a centralised list of all the parts and components in your product. Hence, the most important aspect of a BOM is the Part Name, which should be clearly and accurately mentioned, along with any relevant details.
Example: Black Cotton-Linen Fabric, Buttons, Black Thread, Brand Label
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Quantities
Depending on the final product you are manufacturing or assembling, you may require certain quantities of each part or component, which must be mentioned on the BOM. Remember that a specific product may utilise multiple same or similar parts with slight differences, making it even more important to utilise the BOM for effective tracking of availability and usage.
Example: 2.5 Metres of Black Cotton-Linen Fabric, 12 Buttons, 1 Spool of Black Thread, 2 Brand Labels
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Description
You must add a description in your BOM for any part that requires additional explanation. Maybe a particular component is used at multiple stages, or there are specific instructions for using that component. In such cases, you will add any unique instruction or information that might be helpful during assembly or production.
Example: One brand label will be stitched on the inner side of the collar, and the other one at the bottom left corner of the shirt, 2 inches above the edge.
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Manufacturer Details
Whether you rely on multiple manufacturers for sourcing a specific component or buy each component from a different seller, you must add the related details in the BOM to enable easy and seamless tracking.
Example: The Black cotton linen Fabric is sourced from ABC Fabrics Inc. and LMK Textiles Inc.
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Cost of Component/Part
Your BOM can be as detailed as you want, and it is optional to add the price of each component or part right next to where it is mentioned. However, doing so will help you understand the weightage of each component in determining the total product cost.
Example: The cost of 2.5 metres of cotton linen fabric is $20, Buttons cost $3 for 12 buttons, a spool of thread costs $2, and the labels cost $1 each. So the total cost of materials for the shirt will be $27.
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Priority
Conducting a priority analysis of the parts or components once you prepare a list helps you source the critical parts before the others. The ones with higher priority would be the ones with longer lead times or without which the production will have to be halted.
Example: In order of priority, the Black Fabric will have the highest priority, followed by the buttons, followed by the thread, and lastly, the labels.
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Alternative
What happens if a specific component or part mentioned in your BOM is unavailable, thus jeopardising the integrity of your production or assembly process? Hence, mentioning the component that a specific part or component can be replaced with is crucial for continuity.
Example: The alternative for the spool of black thread is a spool of dark grey thread.
2 Types of Bill of Materials You Should Know About
BOMs are generally categorised based on their levels and the nature of your production or assembly process. The primary categorisation is in the form of single-level and multi-level BOMs, however, the production phase is just as important as it affects the supply chain planning.
Single-Level BOM
A single-level BOM is generally the go-to choice for products that can be easily assembled or produced and don’t involve too many parts or sub-assemblies.
Such BOMs will only mention the product name, part names, and their respective quantities without going deeper into the relationship between these components.
For instance, in the case of the black fabric shirt that we discussed earlier, the components only have to be used in the stitching process without any co-dependencies. In this case, each part of the product can be fixed without affecting the other.
Multi-Level BOM
A multi-level BOM is created for products with layers of sub-assemblies and components involved in the production process.
Such BOMs are referred to as indented and represent the hierarchical structure of all the components and related details, especially where sub-assemblies are involved.
For instance, if your final product is a laptop, you will have multiple sub-assemblies for circuit boards and display monitors combining various components, requiring a multi-level BOM.
Now that we know how your BOM can be structured based on the complexity of your product, let us look at the common use cases or types of BOM:
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Manufacturing BOM: Manufacturing Bill of Materials have a visual flow and utilise diagrams and flowcharts that help manufacture a product after EBOMs are created and approved.
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Engineering BOM: An EBOM or engineering Bill of Materials usually has detailed instructions to define a product with a hierarchical structure and explanation for each component.
4 Crucial Benefits of Using a BOM in Manufacturing
1. Manage Your Stock Better
When you produce certain products in your manufacturing facility, you need to be prepared with enough materials to not stall the process.
Managing your inventory efficiently equals half of your production done right, and having a comprehensive and well-structured BOM for each production process will help you maintain steady stock levels of all the required materials.
2. Facilitate Better Planning
Whether you are planning your production or work in process inventory, you need to have the right components in the right quantity and plan everything to the last detail so you can prevent any errors.
Your planning should be detailed and meticulous so that the final product meets the specifications set at the outset. Creating a detailed BOM that takes care of the raw material planning is integral to the production planning process.
3. Save Costs and Time
Any hurdles or lags in the production process can translate into major issues, leading to a spike in production costs.
Not to mention, all the time that gets wasted in the process can be better utilised on other important tasks and activities.
A proper BOM will help you minimise any sourcing-related delays and increase your productivity, helping you stay within the predetermined budget.
4. Centralise Data Across Departments
Even when all the aspects of your manufacturing or assembly process are in order, one of the biggest challenges you are likely to face is ambiguity caused due to decentralised data.
A detailed multi-level BOM can ensure that all the departments involved with the production are in sync and have access to the necessary details, thus boosting performance.
How to Create a BOM?
Now that we have gotten the basics out of the way, let us look at the simple process to follow when creating a Bill of Materials Excel template.
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Get a detailed understanding of the product and set down the goal and objectives associated with it. Filter out irrelevant information and pay attention to crucial aspects, such as the design and other specifics.
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Once your product is defined, list the sub-assemblies and the components/materials involved in the process.
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Gather every detail associated with every part in your BOM so you can make it as comprehensive as possible and track any potential changes over time.
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Organise all the components into a hierarchical structure and arrange all the parts and sub-assemblies to form a logical structure, facilitating your production process.
While the process is simple enough, and you will have an effective BOM by following these simple steps, you may want to save time and prevent manual errors using a Bill of Materials software. In this case, you can opt for a tool like OpenBOM or Arrow’s BOM Tool.
Concluding Remarks
A Bill of Materials is an official, centralised document containing a list of all the parts and components pivotal to the success of a product’s manufacturing process.
It informs the stakeholders involved in the production process everything they need to know about the parts required for product manufacturing. When used right, it can help you plan your inventory and manage your costs effectively.
Contact us through the PACK & SEND website to get assistance with your sourcing and logistic processes.