Different types of Bill Of Materials
BOM= Bill Of Materials
When talking to customers about the configurator, we need to have a parts list of the product when we want to know what the product structure is and how it is described. Then a lot of different BOMs start to pop up in the conversation. The same product can be described in many different ways depending on who created it and for what use. For this blog, I’ve collected what I think are the ten most common ones.
Generally speaking, a bill of materials describes exactly what parts, materials and sub-assemblies are needed to make a product. Different types of BOMs serve different purposes at different stages of the product lifecycle.
Engineering Bill of Materials (EBOM)
An engineering bill of material focuses on the design of the product. It is used by engineers. It lists all components and assemblies as designed in CAD programs. This bill of materials is often used in prototype development or product development projects. Quite often assemblies are influenced by the internal and external logistics of the product, so that production and assembly can be carried out with pictorial instructions from the 3D model.
Manufacturing Bill of Materials (MBOM)
This bill of materials supports production. It is used by the manufacturing teams and contains all the materials, assemblies and tools needed to manufacture the product. For example, instructions for an assembly line are often based on the MBOM. Assemblies follow the factory’s manufacturing processes, load groups and workstations, i.e. certain parts are required at a particular assembly stage to produce a particular assembly.
Sales BOM (Sales BOM)
The Sales BOM supports sales and customer experience. It is used by sales and marketing teams and lists products and their parts as they are seen by the customer. The product is broken down into parts according to the customer’s needs. Each alternative, selectable part is its own entity, or assembly. These assemblies may have different selectable properties.
Service Parts List (Service BOM)
The service parts list supports maintenance and repairs. It is used by service and after-sales teams and lists the spare parts and sub-assemblies needed to maintain the product. An example of this could be a spare parts list for a product. Quite often, the smallest unit in a service parts list may be an assembly, if the repair situation requires the replacement of a broken assembly rather than just the broken component of the assembly.
Configurable parts list (150% BOM)
The name of the 150% parts list describes well the content of the configurable parts list. There are more parts than are required to make a single product. It therefore allows personalisation and customisation of products, as only the desired parts and assemblies are selected from the parts list. It is used by design, engineering or sales teams, depending on whether the sales or manufacturing structure is configured.
Assembly parts list
The assembly parts list supports the manufacture of individual sub-assemblies. It is used by manufacturing teams. This parts list lists the parts needed to produce a specific sub-assembly at a specific stage/workstation in production. An example could be sub-assemblies to be produced in advance, in stock, even if the product itself is made to order.
Single-level parts list
The single-level parts list provides a simplified view. It does not contain any sub-assemblies. It can be used by any team that needs a list of all parts of a product.
Multi-level parts list
A multi-level parts list provides a detailed hierarchical structure. It contains all parts and sub-assemblies in a hierarchical format, such as a car parts list containing the engine, suspension and other sub-assemblies.
Cost-based parts list
The cost-based parts list supports the economic analysis. It is used by financial and production planning teams. This parts list contains cost data for all parts and assemblies and can be used, for example, to calculate total manufacturing costs.
The use of parts lists depends very much on the needs and business models of the company. Choosing the right type of BOM ensures efficiency and clarity in product design, manufacturing and maintenance. Choosing the right type can be challenging because each has its own strengths. Modular product design automatically helps with this challenge as well, helping you to find the right path.

Single-level example BOM from i3D