inventree-mbom

Manufacturing BOM & Routings plugin for InvenTree

Overview

inventree-mbom extends InvenTree with a full Manufacturing BOM (mBOM) capability, adding a dedicated "Manufacturing Routing (mBOM)" tab to every assembly part. It supports:

• Hierarchical process steps (Op 10 → 10.1 Stencil → 10.2 Pick & Place → 10.3 Reflow)
• Central labor and machine rate catalog with dynamic cost propagation
• Reusable process templates that can be applied to any assembly in one click
• Setup Time (fixed/batch) + Run/Cycle Time (per unit) tracked separately
• CO₂ emission factor tracking per machine center
• Full pricing integration: manufacturing costs bridge into InvenTree's native PartPricing system

Features

Central Tariff Catalog

Process Templates

Create reusable templates (e.g. "SMT Assembly Standard") with hierarchical steps. Apply them to any assembly with one click.

Part Routing (mBOM)

Each assembly gets a PartRouting containing RoutingOperation instances:

PartRouting (for Part: Widget PCB)
├── Op 10: SMT Assembly         [Labor: Assembler, Setup: 30min, Cycle: 2min/unit]
│   ├── Op 10.1: Stencil Paste
│   ├── Op 10.2: Pick & Place
│   └── Op 10.3: Reflow
└── Op 20: Final Inspection     [Labor: Engineer, Cycle: 5min/unit]

Cost Formula

Total Operation Cost (batch) = (Setup_min × Rate/min) + (Cycle_min/unit × Rate/min × batch_qty)
Per-Unit Cost = Total Cost ÷ batch_size
Total Assembly Cost = eBOM Material Cost + mBOM Labor Cost + mBOM Machine Cost

Pricing Bridge

When a LaborRate or MachineCenter hourly rate is updated, Django post_save signals automatically call PartPricing.schedule_for_update() on all affected assemblies — no InvenTree core modifications required.

Setup

• Install Install this plugin in the webinterface with the packagename inventree-mbom. Restart both the InvenTree server and worker after installation.
• Enable Enable the plugin in the plugin settings. You need to be signed in as a superuser for this.
• Configure The following configuration options are available in plugin settings:
  • Default Currency: Currency used for manufacturing cost calculations (default: EUR).
  • Cost Decimal Places: Number of decimal places for cost display (default: 4).
  • Auto-Recalculate on Rate Change: Automatically recalculate part pricing when a labor or machine rate is updated.
  • Include Setup Cost in Unit Cost: If enabled, setup (fixed) costs are amortised into the per-unit cost using the standard batch size defined on the routing.

REST API Endpoints

All endpoints are under /plugin/inventree-mbom/:

Running Tests

# From InvenTree root:
python manage.py test inventree_mbom

Architecture & Design Decisions

Why Not a Standalone SPA?

This plugin uses InvenTree's native UserInterfaceMixin + PanelMixin pattern to inject the mBOM tab. The panel renders server-side HTML with vanilla JS for API interactions, matching InvenTree's native look & feel without requiring a separate build pipeline.

Pricing Bridge Strategy

InvenTree's PartPricing.bom_cost only rolls up physical BOM items. Rather than patching InvenTree core, this plugin uses Django's post_save signal on LaborRate/MachineCenter to call PartPricing.schedule_for_update() on affected parts. The cost summary API endpoint provides the full breakdown (material + labor + machine) for display in the UI panel.

Template vs. Instance Pattern

Process Templates are reusable blueprints. When applied to a part, operations are copied (not linked) so engineers can customize times/notes per-part without mutating the global template. The source_template FK is informational only.

License

MIT License - see LICENSE