OpenMES is a free, open-source Manufacturing Execution System designed to help manufacturers manage production orders, monitor shop-floor activity, track quality and materials, and connect production equipment with business systems.

Unlike many MES platforms that require a sales conversation before you can see the software, OpenMES gives manufacturers several ways to evaluate it directly.

You can use the live online demo, inspect the source code on GitHub, or download and deploy OpenMES on your own infrastructure. The software is licensed under AGPL-3.0 and does not charge traditional per-user software licensing fees.

Manufacturing operator using an MES dashboard to monitor production and work orders

That makes OpenMES particularly interesting for smaller manufacturers that want MES functionality but are reluctant to commit to the cost and complexity of a large enterprise implementation.

Can You Try OpenMES Before You Buy?

Yes — and in this case, “try” actually means try.

OpenMES currently provides a live online demo directly from its website. Its GitHub documentation describes the demo as a free account requiring no credit card, with the demo session active for approximately three hours.

OpenMES evaluation options

Live online demo: Yes
Credit card required: No
Software download: Yes
Self-hosted evaluation: Yes
Open-source code: Yes
License: AGPL-3.0
Sales contact required before evaluation: No
Cloud version: Listed as coming soon
Commercial implementation/support: Available

OpenMES also provides installation packages and instructions for self-hosting, including Docker deployment. Recent releases include desktop packages for Windows, macOS and Linux as well as Android support.

OpenMES Demo

Try OpenMES:
https://demo-2.getopenmes.com/

OpenMES website:
https://getopenmes.com/

GitHub repository:
https://github.com/Mes-Open/OpenMes

What Does OpenMES Do?

OpenMES sits between business systems such as ERP and the people, machines and processes running production.

Its purpose is to provide manufacturers with a real-time view of what is being produced, where production stands, what went wrong, what materials were used and how efficiently equipment and workers are operating.

Current OpenMES capabilities include:

  • Production and work-order management
  • Production scheduling
  • Operator work queues
  • Production line management
  • Batch and lot tracking
  • Serial-number tracking
  • Material genealogy and traceability
  • Quality control and defect reporting
  • Scrap tracking
  • Downtime monitoring
  • OEE reporting
  • KPI dashboards
  • Maintenance management
  • Work instructions
  • Shift management
  • Audit logs
  • Production costing
  • Barcode and RFID integration
  • Machine connectivity
  • ERP integration
  • REST APIs

OpenMES can collect machine information using industrial protocols including OPC UA, Modbus and MQTT, allowing production data to flow directly from PLCs, SCADA systems and other shop-floor equipment.

Work Orders and Production Execution

Work orders are central to OpenMES.

Manufacturers can create production orders containing information such as:

  • Order number
  • Product
  • Planned quantity
  • Production line
  • Priority
  • Due date

Orders move through defined production states including pending, accepted, in progress, paused, blocked, completed, rejected and cancelled.

Companies that are not ready for full ERP integration can also import work orders from CSV, XLS or XLSX files and save field mappings for repeated imports.

That may be particularly useful for smaller factories making the transition from spreadsheets toward a more structured MES environment.

Production Scheduling

OpenMES includes production scheduling rather than functioning solely as a shop-floor data collection system.

Production orders can be displayed against production lines using weekly and more detailed planning views. Current releases include minute-level scheduling and Gantt-style planning with the ability to move and resize operations.

For manufacturers comparing MES and production scheduling software, this is worth testing carefully.

Scheduling functionality in an MES can be useful, but it is not necessarily equivalent to the advanced constraint-based planning capabilities provided by dedicated APS software.

OEE and Production Monitoring

OpenMES includes Overall Equipment Effectiveness monitoring and production-performance reporting.

Manufacturers can monitor factors such as:

  • Availability
  • Performance
  • Quality
  • Downtime
  • Production rates
  • Scrap
  • Output versus target
  • Line and workstation performance

The system can obtain production information manually from operators or automatically through connected machines and sensors.

This is one area we would spend considerable time testing during an OpenMES evaluation.

The value of an OEE dashboard depends heavily on whether the data feeding it accurately reflects what actually happens on the factory floor.

Quality Management

OpenMES contains more quality functionality than you might initially expect from a free MES platform.

Capabilities include defect and issue reporting, scrap reason codes, quality checks, Statistical Process Control functionality, inbound inspection, material holds and production traceability.

Operators can record production problems during execution, while managers can review quality and scrap reports afterward.

Recent versions also support categorizing scrap using the familiar 5M Ishikawa categories:

Material, Machine, Method, Man and Environment.

Traceability and Material Genealogy

Traceability is another particularly interesting OpenMES capability.

The software can track production using:

  • Material lots
  • Supplier lots
  • Manufacturing batches
  • Finished-product lots
  • Serial numbers
  • Operators
  • Machines
  • Process steps
  • Quality information
  • Customer orders
  • Pallets

Current versions support both forward and backward traceability, making it possible to follow material from incoming components through production or work backward from finished goods toward the source material and process history.

For manufacturers in regulated or recall-sensitive industries, this deserves serious attention during an evaluation.

Connecting OpenMES to Machines

OpenMES supports several industrial connectivity methods including:

OPC UA
Modbus TCP
MQTT

The system can collect information from PLCs, machines, sensors and SCADA environments and use those signals for functions such as production tracking, machine status, automated downtime and quality monitoring.

That is an important distinction.

Some inexpensive production-management products depend primarily upon operators entering information. OpenMES is increasingly capable of becoming part of the actual manufacturing data infrastructure.

ERP Integration

OpenMES provides APIs for connecting MES and ERP systems.

Its current ERP functionality supports importing work orders and exporting production completion and quality information. OpenMES also advertises integration services for systems including SAP, Microsoft Dynamics, Odoo and Comarch.

However, manufacturers should not assume that selecting OpenMES means an ERP integration will simply appear.

Connecting MES to an existing production environment can involve considerable work involving:

  • Item and product structures
  • Work orders
  • Routings
  • Inventory
  • Material transactions
  • Production confirmations
  • Machine identifiers
  • Employee information
  • Quality records

That integration effort should be part of the evaluation.

Who Is OpenMES For?

OpenMES appears particularly well suited to small and midsized manufacturers that want to move beyond spreadsheets, paper travelers or basic production tracking without immediately purchasing a large enterprise MES platform.

The developers specifically position it for smaller manufacturing environments, including metal fabrication, plastics, woodworking and assembly operations. The broader OpenMES site also references electronics, automotive suppliers, food production, precision manufacturing and pharmaceutical manufacturing.

Potential users include:

  • Job shops
  • Fabricators
  • Assembly operations
  • Plastics manufacturers
  • Small discrete manufacturers
  • Component suppliers
  • Companies replacing paper production travelers
  • Manufacturers wanting inexpensive OEE monitoring
  • Plants needing lot and batch traceability
  • Organizations wanting control of their MES data and source code

OpenMES could also appeal to organizations with internal IT or development resources that want a system they can modify rather than a closed commercial platform.

Open Source Does Not Mean Zero Cost

The software itself is free.

Implementing MES is not.

A manufacturer may still need to spend money or internal resources on:

  • Servers or cloud infrastructure
  • Installation
  • Configuration
  • Machine connectivity
  • ERP integration
  • Data migration
  • Custom workflows
  • Reports
  • Training
  • Support
  • Software maintenance
  • Internal development

OpenMES offers commercial implementation, customization, integration and training services for companies that do not want to handle those jobs themselves.

That makes the economics different from traditional MES rather than magically eliminating implementation cost.

For some manufacturers, that trade-off could be extremely attractive.

For others, paying a commercial MES vendor to assume more responsibility may be worthwhile.

What Should You Test in the OpenMES Demo?

Because OpenMES actually gives you access to the software, do more than browse the dashboard.

Create something.

Start with a realistic production scenario from your own plant.

1. Create a production line

Try creating equipment and production lines that resemble your actual factory structure.

Does OpenMES model your facility naturally, or are you already trying to force your plant into the software’s terminology?

2. Create a product and process

Build one of your real manufacturing processes.

Include several operations and determine whether OpenMES can represent the actual sequence operators follow.

3. Create a work order

Create a realistic order with quantity, priority and due date.

Then follow that order through production.

4. Use the operator interface

This may be more important than the administrative interface.

Shop-floor software succeeds or fails with the people who must use it repeatedly during production.

Can an operator quickly determine:

  • What should I work on?
  • What comes next?
  • How many parts are required?
  • What material should I use?
  • What inspection is required?
  • What do I do when something goes wrong?

5. Record scrap and downtime

Intentionally create a problem.

Report scrap.

Stop a machine.

Create a quality issue.

Then determine how easily a supervisor can identify what happened afterward.

6. Test traceability

If traceability matters to your company, build a small material genealogy.

Start with an incoming lot, consume it during production and see whether you can trace the resulting finished product back through the manufacturing process.

Then try the reverse.

7. Test machine connectivity

Manufacturers seriously considering OpenMES should eventually go beyond the hosted demo.

Deploy a test instance and connect it to a machine, PLC, simulator or IoT device.

The question isn’t simply whether OpenMES supports MQTT, Modbus or OPC UA.

The question is whether OpenMES can reliably collect the production signals your equipment actually provides.

8. Test ERP integration

Use your own workflow wherever possible.

Push an order from your ERP or another test system into OpenMES, execute production, and determine whether the resulting information can make the return trip cleanly.

That is where an impressive MES demonstration often becomes a real MES implementation.

OpenMES Advantages

One of OpenMES’s biggest advantages is also unusually simple:

You can see it.

You do not have to schedule a discovery call before deciding whether the software deserves another hour of your time.

Other potential advantages include:

  • No traditional software license fee
  • Full access to source code
  • Self-hosted deployment
  • No per-user licensing
  • Live demo
  • Growing machine-connectivity capabilities
  • Production scheduling
  • OEE
  • Quality management
  • Lot and serial traceability
  • REST API
  • Active development
  • Commercial implementation services available if needed

The project’s release history also shows substantial development activity during 2026, with new functionality being added frequently.

OpenMES Limitations to Consider

Open source is an advantage, but it changes what you should evaluate.

OpenMES is not backed by the same organization, global partner ecosystem or implementation network as platforms from companies such as Siemens, Rockwell Automation, Dassault Systèmes or SAP.

Manufacturers should therefore investigate:

  • Long-term project sustainability
  • Release management
  • Security updates
  • Support availability
  • Documentation
  • Partner availability
  • Implementation resources
  • Upgrade compatibility
  • Customization maintenance
  • Regulatory requirements
  • Enterprise scalability

The platform is also evolving quickly.

That is exciting, but rapid development can matter if your manufacturing operation requires a highly stable, heavily validated software environment.

OpenMES vs. Enterprise MES

OpenMES should not automatically be treated as a cheaper substitute for every enterprise MES platform.

A multinational manufacturer operating dozens of complex factories may have very different requirements from a 75-person manufacturer replacing paper travelers in one plant.

Enterprise platforms can offer substantial advantages in areas such as:

  • Large-scale deployment
  • Global governance
  • Corporate IT integration
  • Regulatory validation
  • Vendor support
  • Partner ecosystems
  • Advanced manufacturing models
  • Lifecycle management
  • Enterprise analytics

But those capabilities come with cost and complexity.

OpenMES gives smaller manufacturers another option:

Start with actual production problems instead of starting with a multimillion-dollar software architecture.

That alone makes it worth evaluating.

Is OpenMES Really Free?

The OpenMES software is currently released under the GNU Affero General Public License version 3 (AGPL-3.0) and can be downloaded and self-hosted without traditional license fees.

Organizations planning to modify the software should review the AGPL licensing requirements carefully, particularly requirements surrounding distribution and making modified source code available when software is provided over a network.

Companies that do not want to install and customize OpenMES themselves can purchase commercial implementation and integration services.

Our Take

OpenMES may be one of the more interesting MES evaluations for a small manufacturer precisely because there is so little preventing you from evaluating it.

There is no reason to spend the first evaluation meeting watching someone else operate a carefully prepared demonstration.

Open the demo. Create a work order. Break something. Report some scrap. Trace a lot.

Then decide whether OpenMES deserves space on your production floor.

For manufacturers with technical resources, take the evaluation one step further: install it, connect something to it and find out how well it handles your manufacturing process rather than the developer’s demonstration process.

That is what a software evaluation should be.