MES — Manufacturing Execution System
MES (Manufacturing Execution System) is the software layer between the ERP and the shop floor — between strategic production planning and the actual machines, operators and inspection stations. MES collects real-time data from production, executes the detailed shop-floor schedule released from ERP/APS, and reports actuals back to the ERP for costing and inventory updates.
Core MES functions
- Detailed scheduling: dispatching individual operations to machines and operators
- Shop-floor data collection (BDE): actual start/end times, scrap, rework, downtime causes — usually via touchscreen, scanner or direct machine connection
- Machine data collection (MDE): real-time signals from machines via OPC UA
- Quality management: in-line inspection, SPC charts, deviation handling
- Traceability: batch- and serial-number tracking, mandatory in pharma, food, automotive
- Tool and resource management: tool wear tracking, calibration intervals, operator certifications
MES vs ERP's native production module
Most ERP systems include a production-planning module that handles basic shop-floor data entry and dispatching. For simple assembly with few variants, this is sufficient. MES becomes necessary when: real-time machine data drives planning decisions, regulatory traceability is required (pharma GxP, automotive IATF 16949), high automation requires sub-minute scheduling, or quality data must be captured at every operation. The boundary is fluid — modern ERP vendors push their production modules upward, MES vendors push their planning capabilities downward.
Leading MES vendors
iTAC (electronics manufacturing), HYDRA by MPDV (broad installation base from automotive to food), Siemens Opcenter Execution, GE Proficy Plant Applications, AVEVA MES, SAP Digital Manufacturing. Specialised industry MES exist for pharma (Werum PAS-X), food and beverage, and aerospace. Implementation budgets typically run 100,000-1,000,000 EUR per plant.
Related Topics
Frequently Asked Questions
Can I run manufacturing without MES?
Yes, for many mid-market manufacturers. If your production is well understood, variants are limited, and operators reliably enter accurate data into the ERP, the ERP's native production module is usually enough. MES becomes valuable above a complexity threshold: roughly 50+ active production orders simultaneously, more than 10 work centres with frequent reassignments, or regulatory traceability requirements.
What is the difference between MES and SCADA?
SCADA controls and monitors machines and process equipment — temperature, pressure, valve positions. MES sits above SCADA and translates machine signals into business meaning (production progress, scrap rates, OEE). Large plants run all three layers; small plants may collapse SCADA and MES.
Does Industry 4.0 replace MES?
No. Industry 4.0 and IIoT extend MES rather than replace it. Modern MES platforms integrate OPC UA, MQTT and edge-computing capabilities to handle direct machine data flows. The functional core (scheduling, BDE/MDE, traceability, quality) remains. New entrants like Tulip focus on rapid configurability rather than replacing the classic MES function.