What is MES?
Technical definition
Manufacturing Execution System – the system layer that manages and tracks production in real time: work orders, traceability, quality and material flow. MES sits between the business system (ERP) and automation, corresponding to level 3 in the ISA-95 hierarchy.
In brief
MES is the factory’s operational brain: where orders become actual production and where production data becomes traceable history.
The Challenge
In many facilities, the gap between business systems and automation is filled by spreadsheets, whiteboards and verbal routines. Orders are printed on paper, quality data is typed in afterwards and traceability is reconstructed manually whenever a customer or authority asks. At the same time, many MES projects fail – not because the system is bad, but because the information structure is missing: without shared identities for equipment, materials and operations, MES becomes yet another island requiring manual translation against SCADA and ERP.
HubMind’s Methodology
We see MES as part of the Engine – but it can only work if the Map exists. Before system selection, we help you define the information model: an equipment hierarchy according to ISA-95, recipe and batch structure according to ISA-88 and a naming convention that holds MES, SCADA and maintenance systems together.
We advocate MES as a data source in an open architecture – preferably publishing to a UNS – rather than a monolith with proprietary integrations. That way you can replace parts without losing the whole, and your MOM capability grows step by step instead of in one large risk project.
Warnings & Pitfalls
“MES first, structure later”: An MES without an information model digitalises the chaos. Identities, hierarchies and material structure must exist before the system is configured.
Feature-list procurement: Every MES has “traceability” on paper. The difference lies in the data model, the integration architecture and how well the system fits your actual flows.
Point-to-point integrations: Custom MES-ERP and MES-SCADA couplings quickly become technical debt. Require standard interfaces and documented data mapping.
💡Our Recommendation
Define the information model first: Equipment, materials and operations with shared identities – before system selection.
Require ISA-95 alignment: The system’s data model must map to your hierarchy, not the other way around.
Start where it hurts most: Usually traceability or order reporting. Expand stepwise towards full MOM capability.
Keep the ownership: Mappings, identities and historical data are yours – write it into the contract.
FAQ
What is the difference between MES and SCADA? SCADA monitors and controls the process in real time (level 2). MES manages production as a business activity – orders, traceability, quality (level 3). SCADA knows what the valve is doing; MES knows why.
What is the difference between MES and MOM? MOM is the whole operations domain (production, quality, maintenance, logistics). MES is a system category supporting parts of MOM.
Do smaller facilities need MES? Perhaps not a full-scale system – but everyone needs the MES capabilities: order management, traceability and production follow-up. Sometimes a well-structured combination of SCADA, historian and reporting tools is enough.
HubMind’s related pages:
ISA-95, ISA-88 and the Purdue Model
Weihenstephan Standards – the common language
Industry resources:
MESA International – Industry association for MES/MOM
Planning an MES – or struggling with one that never got finished?
HubMind helps you define the information model, requirements and integration architecture – before the supplier defines them for you.