MES-System: What is an MES? Explanation, definition, and functions
Downtimes, unplanned rework and a lack of transparency on the shop floor cost time, money and nerves: If you don't see in real time what is being produced, where quality is slipping, and which orders are overdue, lead times and on-time delivery quickly deteriorate. An MES system brings structure, data transparency and operational control to manufacturing. But what exactly is an MES system and what tasks does it take on in day-to-day operations?
1. What is an MES system? Explanation and Definition
What is an MES system: MES stands for Manufacturing Execution System and refers to a software solution that plans, controls, monitors and documents manufacturing processes in real time. This explanation hits the point: An MES sits operationally close to machines, lines and employees (shop floor) and makes production measurable, traceable and controllable.As a compact definition you can remember: An MES collects production data (current state), implements specifications (target state) and provides decisions and evidence (e.g., quality, traceability).
In many companies, MES is the data hub between higher-level planning (e.g., ERP) and implementation in production (e.g., machine controls). Important: Not every product on the market covers all tasks; many solutions are modular and focus on particular areas such as detailed planning, data collection, quality management, or monitoring.
2. Why do you need an MES? Goals and benefits
An MES pays off when decisions in production should be made faster and based on facts, instead of working with Excel lists, verbal instructions or daily reports. Typical goals are better schedule adherence, shorter lead times, less scrap, fewer stoppages, and transparent metrics across shifts, lines and plants.
Practical benefits in manufacturing:
- ✅ Real-time transparency: Order status, machine states, quantities, times and quality are currently visible.
- ✅ Responsiveness: Disruptions are detected early, actions can be initiated faster.
- ✅ Efficiency: Resources (materials, personnel, equipment) can be planned and utilized more reliably.
- ✅ Records: Documentation for audits, complaints and traceability becomes easier (critical depending on industry).
- ⚠️ Prerequisite: The benefit increases strongly with data quality, clean process definitions and good machine integration.
3. Core functions of an MES (Practical Checklist)
An MES bundles several functional areas that together enable operational production control. As an established reference framework, common task packages include order management, detailed planning, material and personnel topics, data collection, quality management and performance analysis.
| Functional area | What does it entail in practice? | Typical results |
|---|---|---|
| Functional area Order management | What does it entail in practice? Structure orders into work steps, control sequences, track progress. | Typical results Status per order, bottleneck indications, prioritizations |
| Functional area Detailed planning and control | What does it entail in practice? Break down capacities to specific machines, times and personnel; adapt dynamically in case of disruptions. | Typical results Reliable production control center, less re-planning chaos |
| Functional area Data collection (BDE/MDE/PDE/QDE) | What does it entail in practice? Capture of operating data (BDE), machine data (MDE), process and quality data as the basis for real-time transparency. | Typical results Valid current state, fewer manual lists |
| Functional area Manufacturing monitoring | What does it entail in practice? Real-time overview: Where is which order, which machine is running, where are disruptions occurring? | Typical results Shop floor boards, alarms, escalations |
| Functional area Quality management | What does it entail in practice? Inspection plans, inspection characteristics, holds, deviations, rework and evaluations. | Typical results Less scrap, traceable quality |
| Functional area Performance analysis and KPIs | What does it entail in practice? KPIs such as OEE, scrap rate, throughput time, utilization, schedule adherence consolidated and analyzed. | Typical results Root-cause analyses, continuous improvement impulses |
| Functional area Material and production logistics | What does it entail in practice? Material provisioning, WIP transparency, bookings and feedback along production (depending on solution). | Typical results Fewer material shortages, more stable processes |
| Functional area Energy management | What does it entail in practice? Recording and allocation of energy consumption to equipment, orders or shifts (optional). | Typical results Energy KPIs, identifying cost drivers |
| Functional area Maintenance (e.g., TPM) | What does it entail in practice? Alarm signals, maintenance plans, condition-based indications (optional, depending on provider). | Typical results Fewer unplanned stoppages |
Important in practice: An MES is rarely just “one screen.” It is a system of processes, roles (operators, shift supervisors, AV, QA), data rules and interfaces that structure day-to-day production.
4. MES vs. ERP vs. SCADA/SPS: Distinction
Many misunderstandings arise because ERP, MES and automation use similar terms but fulfill different roles. A good target picture is: ERP plans business-wise and roughly, MES controls operationally and precisely, SCADA/SPS regulates technically and directly at the plant.
| System | Primary focus | Time horizon | Typical data |
|---|---|---|---|
| System ERP | Primary focus Orders, materials, schedules, costs, customers, purchasing, inventory | Time horizon Days to months | Typical data BOMs, work plans, stocks, requirements |
| System MES | Primary focus Implementation on the shop floor: detailed planning, feedback, quality, KPIs | Time horizon Minutes to days | Typical data Machine states, progress, scrap, test values |
| System SCADA | Primary focus Process visualization and monitoring of technical systems | Time horizon Seconds to minutes | Typical data Signals, measurements, alarms, trends |
| System PLC/SPS | Primary focus Machine control in real time | Time horizon Milliseconds to seconds | Typical data Inputs and outputs, control loops, states |
- ✅ An MES does not replace an ERP, but complements the operational level.
- ✅ An MES does not replace a PLC, but uses its data and provides inputs or feedback logic.
- ⚠️ If your ERP already performs a lot of detailed planning, an MES often remains worthwhile due to real-time data, quality logic, traceability and shop floor usability.
5. Data, architecture and standards (e.g., OPC UA, VDI 5600)
An MES thrives on data flows: order data typically comes from enterprise planning, while current-state data comes from machines, terminals and quality recording. In manufacturing practice, several data types arise: operating data (BDE), machine data (MDE), process data, personnel data and quality data.
Standards and references help to define scope and interfaces cleanly:
- ✅ VDI 5600 is frequently used as a reference for typical MES task packages (e.g., order management, detailed planning, data collection, quality management, performance analysis).
- ✅ OPC UA is a common standard for data exchange between machines from different manufacturers and higher-level systems; it also supports security mechanisms such as certificates and encryption.
- ⚠️ “Standard available” does not mean “implementation finished”: in projects, data model, naming, timestamp logic and plausibility checks are usually the critical details.
Cloud, on-premises, or hybrid: many MES solutions today offer different operating models. In highly regulated environments, data sovereignty, network isolation and auditability play a bigger role, while other companies prioritize fast scalability and lower infrastructure effort.
| Operating model | Strengths | Typical risks |
|---|---|---|
| Operating model On-premises | Strengths Full control over infrastructure, network, data storage | Typical risks Higher operational effort, update and patch burden |
| Operating model Cloud | Strengths Rapid scalability, often shorter release cycles, easier remote access | Typical risks Dependence on connectivity, data privacy and compliance checks required |
| Operating model Hybrid | Strengths Shop-floor-close locally, analytics and reporting optional in the cloud | Typical risks More complex architecture, clear responsibilities required |
Table of Contents
- What is an MES System? Explanation and Definition
- What is an MES Used For? Goals and Benefits
- Core Functions of an MES (Practical Checklist)
- MES vs. ERP vs. SCADA/PLC: Distinction
- Data, Architecture and Standards (e.g., OPC UA, VDI 5600)
- Implementation of an MES: Approach, Effort, Pitfalls
- MES Selection Criteria and Vendor Comparison Logic
- MES and abas ERP: Interplay in SMEs
- Frequently Asked Questions
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6. Introducing MES: Approach, Effort, Pitfalls
An MES project is less about “installing software” and more about setting up an “operating system for manufacturing.” If you proceed methodically, you will avoid typical frustration points such as data sprawl, acceptance problems, or unreliable KPIs.
Practical, proven sequence:
- ✅ Define target state: Which 3 to 5 KPIs and decisions should improve in real time (e.g., OEE, on-time delivery, scrap, setup time)?
- ✅ Define processes: feedback points, disruption-reason catalogs, quality checks, roles and responsibilities.
- ✅ Clarify data sources: Which machines provide which signals, where are terminals needed, scanners, and manual inputs?
- ✅ Start a pilot: One line or a product area, clearly delineated, with measurable before-and-after comparisons.
- ✅ Scale: Roll out after stable master data, proper training, and robust analyses.
Common pitfalls:
- ⚠️ Unclear definitions (e.g., “downtime”, “scrap”, “good quantity”) lead to KPIs that no one trusts.
- ⚠️ Too many goals at once: First stabilize transparency and data collection, then expand automation and optimization.
- ❌ “We do it like before, just digital”: An MES is most effective when processes are consciously simplified and standardized.
7. MES selection criteria and vendor comparison logic
The best MES solution is the one that measurably reduces your bottlenecks and reliably operates on the shop floor. Use a clear evaluation logic for the selection, rather than just comparing feature lists.
Selection criteria that prove themselves in projects:
- ✅ Manufacturing type: Discrete manufacturing, process manufacturing, variant manufacturing, assembly, batches, lot sizes.
- ✅ Data integration: machines, sensors, scanners, scales, laboratory equipment, terminals; existing standards such as OPC UA.
- ✅ Usability on the shop floor: fast screens, offline capability (if needed), multilingual support, roles and permissions.
- ✅ Quality and traceability requirements: inspection plans, lockout logic, approvals, audit trail.
- ✅ Reporting and analytics: KPI models (e.g., OEE), drill-down, shift reports, root-ccause analysis.
- ⚠️ Customizing vs. standard: The more custom logic, the higher the effort and test burden during updates.
Practical tip: Have providers map a real-use case as a mini-demo, for example “rush order with material shortage and quality deviation,” including feedback, blocking, escalation, and KPI impact.
8. MES and Abas ERP: Interaction in the mid-market
Abas is an ERP solution for the mid-market with a focus on production and manufacturing companies and is commonly used as ERP for SMEs and as ERP for production (also as Cloud ERP, depending on the deployment model). In practice, the added value often arises when Abas provides the business planning and master data and an MES controls execution in real time on the shop floor.
Typical allocation of tasks between Abas ERP and MES:
- ✅ Abas ERP: customer orders, materials management, bills of materials, operations plans, rough scheduling, purchasing, warehousing, cost centers and business processes.
- ✅ MES: detailed planning, feedback (quantities, times, disruptions), machine states, quality checks, operator guidance, KPI analyses.
- ⚠️ Critical success factor: clear interface logic, e.g., which data are leading (master data in ERP, actual data in MES) and when feedback is posted.
Important use cases around Abas in the MES context:
- ✅ Transfer production orders from Abas to the MES so that the control room and shop floor work with the same order data.
- ✅ Feed back from the MES (progress, times, scrap, quality status) to Abas so that inventories, costing and scheduling information are reliable.
- ✅ Material provisioning and consumption: If the MES records material movements and feedback, Abas can build on that to maintain consistent inventories.
- ✅ Cloud ERP plus shop floor: Even if Abas runs as a Cloud ERP, an MES can capture shop-floor near real-time data and connect it with defined handoffs to business processes.
Concrete note from the abas ecosystem: There are reports of MES-to-abas connections via the abas REST API to automatically transfer production orders and to support production planning.
What mid-sized companies should pay particular attention to:
- ✅ Few, robust interfaces instead of many edge cases.
- ✅ Clean master data maintenance in Abas (work steps, resources, bills of materials), otherwise MES planning suffers.
- ✅ Change management: Operators and shift supervisors need clear benefits (less searching, less paperwork, faster decisions).
What is the difference between MES and BDE/MDE?
BDE (Betriebsdatenerfassung) and MDE (Maschinendatenerfassung) are important building blocks, but primarily provide data. A MES also uses this data for control, detailed planning, quality logic and KPI analysis.
From what point does an MES pay off for SMEs?
Often it's already the case when you have multiple production lines, a high variety of variants, demanding schedule adherence, or strong quality and documentation requirements. What matters is less the size of the company and more the complexity and susceptibility to disruptions in production.
Does an MES have to be in real time at all times?
The typical MES added value arises from timely data and control, i.e., close to real time. In some areas, short intervals (e.g., minutes) are sufficient, while fault alerts and machine statuses are often needed much faster.
Which KPIs are particularly important in MES?
Companies often start with OEE, scrap rate, lead time, on-time delivery, and setup times, because these are directly linked to delivery capability and costs.
Is an MES suitable for regulated industries as well?
Yes, it's precisely there that audit trails, traceability, quality checks, and clear documentation are often central drivers. It is important to clarify early in the project the requirements for validation, access rights, and proof of compliance.
How long does an MES implementation take?
It depends heavily on the scope, the level of machine integration, and data quality. A pilot area can become operational relatively quickly, while a plant rollout is more often planned as a multi-phase program.