PLM decoded - What's a BOM?

WARNING: Do not read this post out loud in an airport or on a plane!

What’s a BOM? In the context of companies that design and manufacture products, BOM is short for Bill of Material. I like to think of a BOM as a shopping list of items needed to make a product. If your product is a bicycle, your BOM would include tires, spokes, frame, seat, handlebars, and all the other items needed to build a ready-to-ride bike. It would also include important information like how many of each part is required and which of the seats you stock is the right one for this bike. The BOM might include parts you make and others you purchase. The parts you design in SOLIDWORKS would be listed on your CAD BOM. A product engineer would then take the CAD BOM and add the parts you don’t design, but that are needed to assemble your finished product, to create the engineering BOM (EBOM). So we are done right? Come on you didn’t think it would be that easy did you?

So now that we have the complete list of all the parts needed to make our bike (EBOM) we hand it off to manufacturing. The manufacturing engineer shakes his head and starts breaking the list apart, but why? Sure the product engineers know how to organize the EBOM in a way that makes sense for them but they clearly know very little about how to manufacture the bike. Our manufacturing engineer reorganizes the list and adds new information needed for manufacturing. Items like bearing grease, product decals and other non-designed parts. The reorganized list, now called the manufacturing BOM (MBOM), groups parts together so they are sent to the plant that makes them with the newly added information on which tooling will be required. The portion of the list sent to specific manufacturing plant is called a Plant Specific BOM (PBOM). The brake and shifter cable assemblies are sent to the vendor that supplies these based on our attached specifications. This continues until all the items needed to make our bike have been assigned to a manufacturing plant or vendor.

ENOVIA PLM provides the capabilities to create and manage multiple BOMs, each for a specific purpose. It maintains links across the different BOMs for each part or item. This linking capability is very important for communication between engineering, purchasing, vendors and manufacturing in the event of a design change or the need to use a substitute part downstream in manufacturing to stay on schedule. BOMs provide each group with the information they need for their portion of the process and the ability to efficiently communicate during the design & build of our new bike.