Manage Manufacturing with Bill of Materials (BOM) in ERPNext

Understand how ERPNext's BOM helps you define assemblies, manage components, and control production costs with precision.

Get BOM Support

Create, version, and maintain accurate BOMs to drive predictable manufacturing and reduce material waste.

What is a Bill of Materials (BOM)?

A Bill of Materials (BOM) in ERPNext is the structured list of raw materials, sub-assemblies, components and quantities required to manufacture a finished product. BOMs are the backbone of production planning, costing, and inventory control.

Key Features of BOM in ERPNext

ERPNext provides flexible BOMs to match simple and complex manufacturing scenarios.

Itemized Components

List parts, quantities, units of measure and sourcing details clearly for each finished product.

Multi-level & Sub-assemblies

Create nested BOMs for complex assemblies and manage sub-components independently.

BOM Versions & Effectivity

Maintain multiple BOM revisions and set effectivity dates to control which version is used in production.

Costing & Valuation

Automatically roll up component costs into the finished good for accurate product costing and profitability analysis.

Seamless Production Integration

Link BOMs to Work Orders, Job Cards and Production Planning to streamline manufacturing execution.

Material Reservation & Substitution

Reserve stock for production and define valid substitutes to avoid delays during shortages.

BOM Types & When to Use Them

Choose the right BOM structure to match your product complexity and production process.

Single-level BOM

Best for simple products where finished goods are built directly from raw materials.

Multi-level BOM

Use for assemblies with sub-assemblies and hierarchical part lists.

BOM with Routings

Includes operations and labor steps for detailed work order planning.

Phantom / Virtual BOM

Temporary assemblies used only during production; not stocked as separate items.

BOM Creation & Approval Workflow

ERPNext simplifies BOM lifecycle from creation to approval and effectivity.

1. Create BOM

Define components, quantities, scrap %, and operations for the product.

2. Review & Approve

Route BOM for engineering and production approvals with comments and version control.

3. Set Effectivity

Specify start/end dates or batch/serial constraints for BOM applicability.

4. Use in Production

Auto-populate Work Orders and reserve materials to begin manufacturing.

Best Practices for BOM Management

Maintain accurate BOMs to reduce production errors, improve costing, and speed up assembly.

✔ Keep a single source of truth — store BOMs in ERPNext and avoid spreadsheets.
✔ Use clear part descriptions and standardized units of measure.
✔ Maintain BOM versions and document why changes were made.
✔ Link BOMs to routings and workstations for accurate lead time calculation.
✔ Regularly audit BOMs against physical assemblies to prevent drift.

Need Help Setting Up BOMs?

Our ERPNext consultants will help you design product structures, migrate legacy BOMs, and train your production team.

Talk to an Expert