In modern manufacturing, both Manufacturing Execution Systems (MES) and Enterprise Resource Planning (ERP) play essential roles.
ERP systems manage business-level processes such as order handling, purchasing, and resource planning. MES systems manage the operational layer — scheduling, data collection, quality, and real-time execution.
They are not competitors but complementary components of a unified digital manufacturing strategy. The key question is how effectively they are integrated to ensure continuous data flow, transparency, and responsiveness across all levels of production.
| Dimension | ERP System | MES System |
|---|---|---|
| ISA-95 Level | Level 4 – Business Planning & Logistics | Level 3 – Manufacturing Operations Management |
| Time Horizon | Planning range (days – weeks) | Real-time control (seconds – minutes) |
| Primary Functions | Order management, materials, HR, finance, logistics | Production control, scheduling, BDE/MDE, quality, reporting |
| Data Type | Aggregated planning and booking data | Real-time process and machine data |
| Decision Level | Strategic & tactical | Operational |
| Key KPIs | Delivery reliability, cost, inventory, revenue | OEE, scrap rate, downtime, throughput |
| Users | Management, controlling, planning | Supervisors, line managers, operators |
ERP defines what and when. MES ensures how and with what.
Together, they form a closed-loop manufacturing control system.
ERP systems were historically designed for administrative processes. They reach their limits where real-time visibility, detailed execution, and traceability are required.
MES extends the ERP layer by:
Translating ERP work orders into machine-level tasks and sequences
Collecting machine and operator data (MDE/BDE) automatically
Tracking performance, quality, and material consumption in real time
Sending standardized feedback back to the ERP for cost and progress reporting
The result is a continuous information loop between planning and execution.
A robust MES-ERP integration relies on consistent data models and secure interfaces.
Typical data flow:
ERP → MES: production orders, BOMs, routings, material and shift data
MES → ERP: quantities, production times, scrap, equipment states, quality results
Interface standards: REST API, OPC UA, MQTT, SAP IDoc, XML/CSV.
Integration modes: real-time (push/pull), event-driven, or batch synchronization.
This bidirectional communication ensures consistent master data, eliminates manual re-entry, and enables traceable performance reporting.
According to ISA-95, ERP (Level 4) and automation systems (Levels 2–1) operate on different layers.
MES, positioned on Level 3, acts as the operational middleware that connects both worlds:
Aggregates machine and sensor data into structured KPIs
Visualizes OEE, quality deviations, and material flows in real time
Enables feedback to business systems for costing and delivery analytics
Provides the foundation for Industry 4.0, predictive maintenance, and digital twins
MES is therefore the execution backbone bridging production technology and business planning.
SYMESTIC Cloud MES provides standardized connectors for major ERP systems (SAP S/4HANA, Microsoft Dynamics 365, proALPHA, Infor, abas).
Key integration features:
Automated data exchange via open REST and OPC interfaces
Synchronized order status including progress, quantities, and quality
OEE and performance metrics transferred back to ERP dashboards
Central master-data consistency for materials, resources, personnel
Scalable cloud architecture with minimal IT overhead
The result: unified production visibility, fewer manual transactions, and data-driven decision-making across departments.
Companies operating fully integrated MES-ERP environments typically achieve measurable improvements:
+10–20 % equipment availability through real-time monitoring
–50 % manual reporting effort via automated feedback loops
Improved schedule adherence and cost accuracy through live data
Faster decision cycles supported by consistent KPIs
Foundation for Industry 4.0 and Smart Factory initiatives
Integration creates value through data coherence and process synchronization, not system overlap.
Key success factors for sustainable MES-ERP integration:
Data harmonization: unified structures for materials, operations, and resources
Clear IT governance: ownership of data and interfaces
Scalable architecture: choice between direct API coupling or middleware gateway
Change management: cross-functional collaboration between IT and operations
Cybersecurity: encrypted communication, role-based access, audit logging
When implemented correctly, ERP remains the planning backbone while MES governs operational control — both aligned through shared data semantics.
MES and ERP address different levels of the manufacturing value chain.
ERP provides business planning and cost control, MES delivers shop-floor visibility and execution precision.
Their integration forms the foundation of a data-driven, adaptive, and competitive production environment.
In essence:
ERP manages the plan.
MES manages the reality.
Together, they create the digital backbone of modern manufacturing.