Best Free & Open-Source Inventory & Materials Management Solutions For Manufacturers

If your material plan lives in Excel, your shop is already paying for it - in rush orders, missing stock, and production delays that arrive out of nowhere. Inventory and MRP systems connect purchasing, stock levels, and production demand so that material is where it should be, when it should be, without guesswork.

There are solid free and open source systems that handle inventory, materials planning, and basic MRP, and they work well for machine shops and small manufacturers.

1. ERPNext

Best for: All in one MRP + inventory + production for SMEs.

ERPNext is one of the strongest open source options for manufacturers. It covers items, BOMs, work orders, stock locations, reorder rules, and MRP. You get demand driven material plans, purchase suggestions, and real time stock levels tied to production orders. Web based, with good role based permissions and plenty of community extensions.

• Strengths: True MRP, decent manufacturing model, strong community.
• Weaknesses: Requires proper setup and admin discipline.

License: GPLv3, open source.

2. Odoo Community Edition (Inventory + MRP)

Best for: Modular MRP that can start from just inventory.

Odoo CE gives you Inventory, Purchase, Sales, and Manufacturing apps that plug together. You can start with simple stock tracking and reorder rules, then add BOMs and work orders. Barcode support, multiple warehouses, and routes (make to order, make to stock) are all there. Community modules add more manufacturing depth if you need it later.

• Strengths: Modern UI, huge ecosystem, easy to extend.
• Weaknesses: Some advanced features live in Enterprise, so you need to know where the line is.

License: LGPLv3, open core.

3. Dolibarr ERP & CRM (Products & Stock)

Best for: Small shops moving off spreadsheets.

Dolibarr is light, simple, and good enough for many small metalworking or job shops. It covers products, stock locations, suppliers, purchase orders, and basic manufacturing via optional modules. Not a full APS or MES system, but a realistic starting point for keeping materials under control without heavy IT.

• Strengths: Easy to install, easy to teach, low overhead.
• Weaknesses: Limited advanced manufacturing features out of the box.

License: GPLv3, open source.

4. Metasfresh

Best for: Growing SMEs with serious supply chain needs.

Metasfresh is an open source ERP with strong inventory and purchasing. It handles multiple warehouses, batch and lot management, procurement planning, and integrations. Manufacturing modules support make to stock and make to order flows, with material availability checks that matter when you run many SKUs.

• Strengths: Robust, built for industrial use, active development.
• Weaknesses: Heavier to implement than Dolibarr or simple inventory tools.

License: GPLv2, open source.

5. Tryton

Best for: Teams that want a clean, Python based framework.

Tryton is a modular ERP where inventory, purchase, and production are separate modules. You get multi location stock, MTO/MTS flows, reorder points, and simple production. Because it is a framework, it is attractive if you have developers who want to shape the logic to your shop instead of forcing your processes into a rigid box.

• Strengths: Clean architecture, flexible, good for custom flows.
• Weaknesses: Not plug and play for non technical users.

License: GPLv3, open source.

6. OpenBoxes

Best for: Stock and replenishment across multiple locations.

OpenBoxes was born in healthcare supply chains but works well for any environment with multiple stores and steady material movement. It handles stock cards, lots, expiries, reorder rules, and shipment tracking between locations.

• Strengths: Strong core inventory logic, proven in rough environments.
• Weaknesses: Less manufacturing specific, more about logistics.

License: GPLv3, open source.

7. InvenTree

Best for: Parts and component inventory with BoMs.

InvenTree is an open source inventory system focused on parts, assemblies, and BoMs. It supports tracking across locations, minimum stock, purchase suggestions, and API integration.

• Strengths: Great for component heavy environments and BoM tracking.
• Weaknesses: Not a full ERP, basic MRP.

License: MIT, open source.

8. FrontAccounting ERP

Best for: Accounting centric MRP for very small shops.

FrontAccounting covers items, stock locations, purchasing, and simple sales linked to inventory. Lightweight and practical for very small operations.

• Strengths: Lightweight, simple, cheap hosting.
• Weaknesses: Dated UI, limited manufacturing depth.

License: GPLv3, open source.

9. Snipe IT

Best for: Managing tools, fixtures, and gauges as inventory.

Snipe IT is asset tracking, not MRP, but solves tooling chaos: labels, assignments, barcodes, QR codes.

• Strengths: Great UX, easy to deploy.
• Weaknesses: No MRP logic.

License: GPLv3, open source.

10. OpenBoxes + Node RED / ETL pattern

Best for: Connecting stock to real time consumption.

Use OpenBoxes (or ERPNext / Odoo) for stock and master data, then connect shop floor through Node RED or ETL flows.

• decrement material when a pallet is scanned
• trigger purchase requests on min level
• drive kanban cards digitally

This turns your inventory system into a live reflection of consumption.

• Strengths: Bridges IT and OT.
• Weaknesses: Requires someone who can wire flows and APIs.

License: All components open source.

Material Management Solution Comparison

How to choose material planning system for a machine shop

If you want:

• A real ERP + MRP backbone - ERPNext or Odoo CE.
• Something light but structured - Dolibarr or FrontAccounting paired with InvenTree.
• Strong logistics and multi site stock - OpenBoxes or Metasfresh.
• A developer friendly framework - Tryton.
• Tooling control first - Snipe IT.

Minimal viable MRP stack

For a typical CNC or fabrication shop that wants sane material control:

1. Use ERPNext or Odoo CE for items, suppliers, BOMs, work orders.
2. Define min / max levels and lead times for key materials.
3. Enforce all receipts and issues through the system.
4. Add InvenTree for complex assemblies.
5. Link machine data to consumption later via ETL or Node RED.

That alone removes most of the out of stock chaos. The rest is continuous improvement.

About MDCplus

Our key features are real time machine monitoring, energy tracking, CMMS for downtime reduction, and vibration diagnostics for predictive maintenance. MDCplus works across aerospace, automotive, machining, and heavy industry.