Bill of materials (BOM)

What to include when creating a bill of materials

One of the main functions of the bill of materials is to enable maintenance workers to maintain and repair equipment as quickly and efficiently as possible to keep production going. To do so, a best practice is to include specific pieces of information in the bill of materials record. Below is a high-level list of what should be included:

• BOM level - Assign each part a number that indicates where it fits in the hierarchy of the bill of materials.
• Part number - Assign each part a number that allows workers to reference and identify parts quickly within the bill of materials. Be careful not to create multiple part numbers for the same part.
• Part name - Give each part a unique name to help you identify parts more easily.
• Phase - Record what stage each part is at in its asset lifecycle. For parts in production, it is common to use a term like ‘In Production’ to indicate the stage of the part. Other categories can be classified as ‘Unreleased’ or ‘In Design’. This is helpful when implementing a new product into production because it allows you to easily track progress and create realistic project timelines.
• Description - Provide a detailed description of each part that will help you distinguish between similar parts. It also helps you identify specific parts more easily.
• Quantity - Record the number of parts to be used in each assembly or subassembly to help guide purchasing and manufacturing decisions and activities.
• Unit of measure - Classify the unit of measurement when parts are used or purchased. Depending on the part, you could use ‘each’ or standard measures like inches, feet, and ounces. What’s most important is to be consistent across all similar part types so that the right quantities are procured and delivered to the production line.
• Procurement type - Record the steps involved in inventory management, such as the purchase or production of each part. For example, is the part purchased off-the-shelf or made-to-specification? This will create efficiencies in manufacturing, planning, and procurement activities.
• Reference designators - If your product contains printed circuit board assemblies, include reference designators that detail where the part fits on the board in your bill of materials. Capturing this information in the BOM can save time and help you avoid confusion down the road.
• BOM notes - Document other relevant notes that will be beneficial to know for anyone who interacts with your bill of materials.