BOM 101: 8 Tips for Creating a Successful Bill of Materials
In the first part of our BOM 101 series, we discussed what a bill of materials was — a comprehensive list of raw materials, assemblies and sub-assemblies, components and other critical items for product engineering and manufacturing — and highlighted the six steps we recommend to properly prepare your BOM to set your team and next product launch up for success.
For the second part, we’ll be diving a little deeper and talking more about best practices for creating an effective BOM to improve your team’s communication and collaboration, as well as what specific data points to include to ensure the clarity and quality of its information.
BOM 101: 8 Tips for Creating a Successful Bill of Materials
1. Tailor the BOM to Project/Build Needs
Before creating the BOM, decide the priority details that are required from it and design it to meet those requirements. Different companies do BOMs in different ways, and different projects require different methods of organization, information, and features. Customize the BOM according to the unique demands of your project or build.
2. Use a Template
When creating a BOM, it’s important to use one template. Odds are, there will be multiple departments and people creating BOMs, so having one template that is compatible amid the group is recommended. This way, if it’s required to be uploaded into an advanced software application (like a cloud-based one), then it’ll be consistent across the board.
3. Include the Right Amount of Detail
Include as much helpful information as possible in the document because the BOM plays a critical role in explaining the project or build to the people who’ll build it entirely from scratch. The BOM must be as clear, detailed, and accurate as possible. Some types of information aren’t helpful and will only generate confusion, so use your best judgment on this. A general guideline: the more detail, the better.
4. Items to Include in a BOM
The data points and information included in a BOM may differ from build to build, but below are some of the categories of information that are commonly used. Include as much of the following as possible that’s relevant to the assembly or build:
To identify the exact parts required, list the manufacturer’s part number in the BOM. This is how the assembler will ensure the right component is used. Every part number is unique, so there should be minimal confusion.
List the name of the component’s manufacturer to help those using the BOM find the right part. It’s important to take the time to verify each piece is available from the manufacturer before listing it and to ensure it’s suitable for your project or build regarding specifications, cost, and delivery. Verifying this information early on will help avoid the extra time and costs of finding a replacement part later during the production process.
Part Name & Description
It can also be useful to list details about each part in the BOM — e.g., dimensions, part name, color, and other specifications. These details will ensure the right part gets ordered and avoid confusion because of similar elements. Also, list the correct units of measurement with each description and make this a separate column. For items that have multiple possible units of measurement, keep them consistent throughout the document.
The number of each part required is another critical piece of information to include. Keep this information up to date, as it will help in future purchasing negotiations where bulk is ordered versus one-off quantities.
Listing the procurement type in the BOM can also help you obtain the right part. This designation describes how a component is bought or made. For instance, it’s recommended to use the following: P, M, or C, which designate Purchased, Modified, and Custom labels, respectively.
It’s crucial to reference which parts in the BOM are more critical than the others, a practice useful for purchasing activities. For example, it’s necessary to understand which components have the longest lead times and have the highest monetary value because these are components that require more care and visibility. An A, B, C approach to priority analysis is recommended here, where A parts are the most critical and C parts are less critical.
If there’s flexibility regarding a part, include the potential alternate parts in case the component initially requested is unavailable or a change arises. Doing so can reduce the amount of time lost in these situations. Also note whether these alternates are the only acceptable substitutions, or just examples.
BOMs often contain multiple levels, which represent either the main assembly, a sub-assembly, or a component. Each BOM has its own structure that’s divided and marked based on BOM levels to help users navigate the data and understand which parts belong to a given assembly or sub-assembly. A simple 1, 2, 3, etc. format is perfectly acceptable.
List what files are available for each part in the BOM. Best case scenario, there are both CADs and drawings available. It’s also worth documenting the dates these files become available for future engineering changes and recordkeeping.
Ensure the revision level is listed for the BOM. This is important for understanding the changes parts have undergone and what the current part revision level is. This should be as simple as R1, R2, R3, etc. or an A, B, C, etc. suffix.
Comments & Notes
Although not a critical category, a notes or comments section can drastically increase the efficiency of your project or build, especially when problems or unexpected changes arise. This would be the place to put any comments and notes that don’t fit into any other category/column.
5. Double Check the Information
Before uploading or sending the BOM to anyone, check it precisely to make sure all the included information is correct and the document can be navigated the way it was intended. Even relatively small mistakes can be costly in terms of time and money.
6. Track Changes
Put a system in place to keep track of all changes to the document. This can be a record of all previous versions and revisions of the BOM; what changes were made, who made them, and when. Make sure each version is clearly labeled and that the most up-to-date one is always being used for the project or build.
7. Limit Access
Although many people in your department or organization may need access to the BOM, don’t give editing permission to someone unless it’s necessary. Instead, give people read-only access to the BOM. Restricting modification abilities will reduce “human error” and prevent accidental and misinformed changes. Also, consider creating a unique identifier for everyone with editing capabilities, so questions about the information in the BOM can always be directed to the correct person.
8. Automate, Automate, Automate
Consider introducing aspects of automation to your BOM management process. Doing so will help identify discrepancies among records and allow for enhanced traceability. It can also make it easier to import and export information for various file formats. Automation features are more prevalent with dedicated BOM Management systems and may require the purchase of additional software. An automated Plan for Every Part (PFEP) is an ideal option that should always be introduced prior to any production launch. Keep it simple at first then migrate to an automated system.