What is Exploding the Bill of Materials?

Exploding the bill of materials means breaking down the bill of materials for a product into its constituent parts. A bill of materials is the record of the raw materials, sub-assemblies and supplies used to construct a product. It contains a description, unit count, and scrap estimate for each line item.

Example of an Exploded Bill of Materials

Exploding a Bill of Materials (BOM) involves breaking down a product into its components and subcomponents, showing all the materials and parts needed at every level of production. Here is an example:

Finished Product: Bicycle

Level 0: Bicycle (1 unit)

Level 1: Frame Assembly (1 unit)
Level 1: Wheel Assembly (2 units)
Level 1: Chain Assembly (1 unit)
Level 1: Seat Assembly (1 unit)

Detailed Exploded Components:

Frame Assembly (Level 1)

Level 2: Metal Frame (1 unit)
Level 2: Paint (1 liter)
Level 2: Screws (10 units)

Wheel Assembly (Level 1)

Level 2: Tire (2 units per assembly = 4 total)
Level 2: Rim (2 units per assembly = 4 total)
Level 2: Spokes (20 units per assembly = 40 total)
Level 2: Hub (1 unit per assembly = 2 total)

Chain Assembly (Level 1)

Level 2: Chain Links (50 units)
Level 2: Grease (50 grams)

Seat Assembly (Level 1)

Level 2: Seat Cushion (1 unit)
Level 2: Seat Frame (1 unit)
Level 2: Bolts (4 units)

How to Use an Exploded Bill of Materials

An exploded bill of materials is used to determine which items needed for a production run are missing from stock, and so need to be ordered. Bill of materials information can also be used to spot any items in stock that are not required for the production of any goods - these items can then be targeted for elimination.