An MES (manufacturing execution system) is software that manages and records production on the shop floor. It turns plans from ERP into dispatched work orders and tracks how raw materials become finished goods.
An MES sits between business systems and control systems. In the ISA-95 model it lives at Level 3, manufacturing operations, above PLCs and SCADA (Levels 0–2) and below ERP (Level 4). ERP says what to make and when. The MES says how, on which line, with which materials, and records what actually happened.
Typical functions include work-order dispatch, electronic work instructions, material tracking and genealogy, labor and machine data collection, quality checks, and performance reporting such as OEE. ISA-95 groups Level 3 activities into four areas: production, quality, inventory (logistics), and maintenance.
Scope varies by vendor and by plant. Some MES products cover quality and maintenance; others leave those to separate systems. "MES" and "MOM" (manufacturing operations management) are often used interchangeably. Integration with equipment and ERP is usually the largest share of the effort, not the software itself.
MES vs ERP
| MES | ERP | |
|---|---|---|
| ISA-95 level | Level 3, manufacturing operations management | Level 4, business planning and logistics |
| What it decides | How, on which line, with which materials | What to make and when |
| Time scale | Shifts and hours | Days and weeks |
Questions about MES
What is the difference between MES and ERP?
ERP says what to make and when. The MES says how, on which line and with which materials, and records what actually happened. In the ISA-95 model, the MES sits at Level 3 and ERP at Level 4.
Is MES the same as MOM?
In everyday use, often yes. MES and MOM, which stands for manufacturing operations management, are frequently used interchangeably. Scope varies by vendor and plant: some MES products cover quality and maintenance, others leave those to separate systems.
What takes the most effort in an MES project?
Integration. Connecting the MES to equipment and to ERP is usually the largest share of the effort, more than the software itself.
MES in real plants
- Endress+Hauser and MVTec Software: Endress+Hauser Flow in Reinach uses MVTec MERLIC, integrated into its MES, to verify manual flowmeter assembly steps by camera; in use since March 2025.
- Tiffany & Co. and Tulip: Tiffany & Co. uses Tulip apps across jewelry production, from material control to work instructions, at four North American sites with 1,700 users.
- VEKA and Tulip: VEKA, a vinyl window and door extrusion manufacturer, runs Tulip for ERP-driven inspections and production tracking at its Pennsylvania plant, then scaled to Texas, Nevada and North Carolina.
- Test Devices and Tulip: Test Devices by SCHENCK replaced paper travelers with Tulip apps for routing, validation and quality records in spin testing of serialized aerospace parts.
- Innovafeed and Tulip: Innovafeed uses Tulip for production, warehousing and MES functions at its insect farm in Nesle, including container tracking and automated container movements.
Related terms
ISA-95
ISA-95 is an international standard series, also published as IEC 62264, for integrating enterprise business systems with manufacturing control systems.
Process historian
A process historian is a time-series database that collects, compresses and stores data from plant control systems, such as sensor readings, setpoints and alarms, so it can be trended, analyzed and retrieved later.
OEE (overall equipment effectiveness)
OEE (overall equipment effectiveness) is a measure of how effectively a machine or line is used during planned production time.
Digital thread
A digital thread is the connected flow of data that links a product's information across its lifecycle, from design and engineering through manufacturing, inspection and service, so each stage can use and feed back into the others.
Unified namespace (UNS)
A unified namespace (UNS) is an architecture pattern in which plant and business systems publish their current data to one shared, hierarchically organized hub, usually an MQTT broker, instead of exchanging it through point-to-point integrations.