Bill of Materials (BOM)
A comprehensive list of all raw materials, components, sub-assemblies, and quantities required to manufacture a finished product, serving as the foundation for procurement planning and cost estimation.
A Bill of Materials (BOM) is a structured document that lists every item needed to build a product, organized hierarchically from the finished good down to individual components. BOMs include part numbers, descriptions, quantities per unit, unit costs, and supplier information. They are essential for procurement planning, production scheduling, and cost management.
In procurement, the BOM drives purchasing decisions: it determines what needs to be bought, in what quantities, from which suppliers, and when. Changes to the BOM — such as engineering change orders or material substitutions — directly impact sourcing strategies, supplier agreements, and inventory levels. Accurate BOMs are critical for calculating true product costs and identifying savings opportunities.
Practical impact: A value analysis of a product's BOM reveals that 3 of 47 components account for 62% of material cost. Procurement focuses negotiation and dual-sourcing efforts on these three items, achieving 15% unit cost reduction — equivalent to €1.2M annual savings at production volumes.