In modern manufacturing, Bills of Materials (BoMs) are no longer simple lists of components. As products become more customizable, regulations stricter, and supply chains more volatile, manufacturers face a new challenge:
How do you manage product variants, engineering revisions, and multi-level assemblies without losing control over cost, inventory, and production accuracy?
This is where Odoo ERP stands out. Rather than treating BoMs as static documents, Odoo transforms them into living, intelligent structures that adapt to product variants, evolve through versions, and scale across multiple production levels.
This blog explores how Odoo simplifies complex BoM scenarios—from variant-based products to versioned designs and deeply nested multi-level manufacturing structures.
Why BoMs Become Complex in Real-World Manufacturing
Before diving into Odoo, let’s understand why BoMs become difficult to manage.
Most manufacturers deal with at least one of the following:
- Product variants (size, color, material, configuration)
- Engineering changes over time (revisions)
- Sub-assemblies and nested production levels
- Make-to-order or engineer-to-order workflows
- Cost fluctuations due to raw material changes
Traditional ERP systems struggle because they:
- Duplicate BoMs for every variant
- Lose traceability during revisions
- Break when assemblies go beyond two levels
- Fail to connect BoMs with costing and inventory
Odoo addresses these problems natively, without heavy customization.
Understanding BoM Types in Odoo
Odoo supports multiple BoM structures that can coexist seamlessly:
- Single-level BoMs – Simple assemblies
- Multi-level BoMs – Assemblies with sub-assemblies
- Variant BoMs – One BoM serving multiple product variants
- Versioned BoMs – Engineering revisions over time
- Alternative BoMs – Multiple ways to manufacture the same product
This flexibility allows manufacturers to model reality—not force reality into software limitations.
Variant BoMs: One Structure, Multiple Configurations
The Challenge with Product Variants
Consider a product like an industrial control panel available in:
- Multiple voltages
- Different enclosure sizes
- Optional safety modules
Traditional systems often create separate BoMs for each variant, leading to:
- Data duplication
- Maintenance overhead
- Higher risk of errors
How Odoo Handles Variant BoMs Intelligently
Odoo allows you to:
- Create a single master BoM
- Assign components to specific product attributes
- Automatically include or exclude components based on selected variant
For example:
- A higher voltage variant automatically adds a different transformer
- A premium model includes additional safety sensors
- A compact variant removes certain brackets
Result:
One BoM, infinite flexibility.
This dramatically reduces:
- BoM maintenance effort
- Engineering errors
- Inventory misalignment
Versioned BoMs: Managing Engineering Changes Without Chaos
Why BoM Versioning Matters
Engineering changes are inevitable:
- Design improvements
- Supplier changes
- Regulatory updates
- Cost optimization
Without proper versioning:
- Production uses outdated designs
- Cost analysis becomes unreliable
- Traceability is lost
How Odoo Supports BoM Versioning
Odoo allows you to:
- Create multiple BoM versions for the same product
- Activate versions based on:
- Date
- Manufacturing order
- Engineering approval
- Keep historical BoMs intact
This means:
- Old products can still be serviced correctly
- New orders use updated designs
- Audit trails remain intact
Engineering and production finally speak the same language.
Multi-Level BoMs: Scaling Manufacturing Without Losing Control
The Reality of Multi-Level Manufacturing
Most real products aren’t built in one step.
Example:
- Final Product
- Sub-Assembly A
- Components
- Sub-Assembly B
- Components
- Raw Materials
- Components
- Sub-Assembly A
This creates multi-level BoMs, which many ERPs struggle to process correctly.
Odoo’s Multi-Level BoM Engine
Odoo handles multi-level BoMs effortlessly by:
- Automatically exploding BoMs during production
- Generating manufacturing orders for sub-assemblies
- Reserving inventory at each level
- Tracking WIP (Work-In-Progress) accurately
This allows manufacturers to:
- Parallelize production
- Reuse sub-assemblies across products
- Maintain visibility across all levels
Cost Accuracy Across Variants and Levels
The Hidden Cost Problem
When BoMs become complex, costing often breaks:
- Variant costs get averaged incorrectly
- Sub-assembly costs are underestimated
- Overheads are ignored
Odoo’s BoM-Driven Costing
Odoo calculates:
- Component cost per variant
- Operation cost per routing
- Sub-assembly roll-up cost
- Real vs theoretical BoM cost
Manufacturers gain:
- Accurate product margins
- Variant-level profitability insights
- Real-time cost impact of engineering changes
This is critical for pricing, quoting, and strategic decisions.
Alternative BoMs: Flexibility During Supply Chain Disruptions
Odoo also supports Alternative BoMs, allowing manufacturers to:
- Define multiple ways to produce the same product
- Switch components during shortages
- Choose cost-effective alternatives dynamically
This capability became especially critical post-2020, where supply chains demand agility.
Real-World Example: Complex Manufacturing with Odoo BoMs
Scenario: Industrial Equipment Manufacturer
Challenges before Odoo:
- Separate BoMs for every variant
- Manual engineering change tracking
- Cost overruns due to outdated designs
After Odoo implementation:
- Single variant-based BoM structure
- Controlled BoM revisions
- Multi-level manufacturing with WIP tracking
- Accurate cost roll-ups
Outcome:
- 30% reduction in BoM maintenance effort
- Improved production accuracy
- Better profitability visibility
Best Practices for Managing Complex BoMs in Odoo
- Use attributes instead of duplicating BoMs
- Version BoMs formally—never overwrite
- Separate sub-assemblies into reusable products
- Review costing impact after every engineering change
- Train engineering and production teams together
FAQs: Complex BoMs in Odoo
1. Can Odoo handle thousands of variants under one BoM?
Yes. Attribute-based BoMs scale efficiently without duplication.
2. Does Odoo support engineering change control?
Yes, through versioned BoMs and controlled activation.
3. Can sub-assemblies be shared across products?
Absolutely. Odoo encourages modular manufacturing.
4. How does Odoo ensure costing accuracy for variants?
Costs are calculated per variant based on actual components and operations.
5. Is Odoo suitable for engineer-to-order manufacturing?
Yes. Odoo supports make-to-order and engineer-to-order workflows seamlessly.
Conclusion: Complex BoMs Don’t Have to Be Complicated
Complexity in manufacturing is unavoidable—but chaos isn’t.
Odoo transforms BoMs from static lists into dynamic, intelligent manufacturing blueprints that:
- Adapt to variants
- Evolve through versions
- Scale across multiple production levels
- Maintain cost and inventory accuracy
If your manufacturing team struggles with BoM complexity, it’s not a process problem—it’s a tooling problem.
With Odoo, complexity becomes manageable, traceable, and profitable.
Looking to design or optimize complex BoMs in Odoo? Partner with an experienced Odoo implementation team and unlock the full power of modern manufacturing.
