An ERP system can tell you a customer ordered 5,000 units due in three weeks. It has no idea whether the machine making them is running or three hours behind schedule. Where ERP sits in the ISA-95 hierarchy, and why ERP-MES integration is the hard part.
An ERP system can tell you a customer ordered 5,000
units due in three weeks. It has no idea whether the machine that makes
those units is running, down for changeover, or three hours behind
schedule right now — that visibility gap is exactly why ERP and MES
have to work together, not compete.
Enterprise Resource Planning sits at Level 4 of the ANSI/ISA-95
hierarchy — the business planning and logistics layer, covering order
management, high-level scheduling, procurement, and finance. See our
related guide on
MES and ISA-95 for how Level 3 sits directly below it, translating
ERP’s business-level orders into the shop-floor execution detail ERP
was never designed to track in real time.
| System | What it tracks |
|---|---|
| ERP (Level 4) | Customer orders, high-level production schedules, procurement, finance, and inventory at a planning level |
| MES (Level 3) | Real-time work order status, machine and labor data, in-process quality, and material consumption on the floor |
Data has to flow both directions for ERP and MES to work together:
order and material requirements flow down from ERP to guide production,
while actual output, scrap, and material consumption flow back up so
ERP’s inventory and cost figures reflect reality instead of a plan that
never quite matched what happened on the floor. Most digital
transformation projects that stall do so at exactly this
integration point, not at either system individually — manual
re-entry between the two defeats the purpose of having both.
Selecting specific ERP or MES software is usually a smaller decision
than getting internal agreement on what data needs to flow where, on
what schedule, and who owns correcting it when the two systems
disagree. Facilities that map their actual order-to-cash and
plan-to-produce workflows before selecting software tend to have
dramatically smoother implementations than those that buy first and
figure out the workflow afterward.
ERP and MES integration planning fits inside the work covered in
SCMEP’s Digital Transformation
programs. As a NIST Manufacturing Extension
Partnership affiliate serving South Carolina manufacturers since
1989, our focus is helping teams map their actual workflows before
choosing or integrating software, not selling a specific platform.
If your team is planning an ERP or MES implementation or struggling
with data flowing between the two, you can
browse the Industry 4.0 and Digital
training catalog or email the training team.
ERP and MES handle planning and execution data; a related system handles the instructions operators actually follow at each station. See our related guide on digital work instructions for how paperless systems connect to that same data flow.
ERP sits at Level 4 of the ANSI/ISA-95 hierarchy, the business planning and logistics layer covering order management, high-level scheduling, procurement, and finance, above the plant-floor execution systems.
ERP tracks customer orders, high-level schedules, and finance at a planning level. MES tracks real-time work order status, machine and labor data, in-process quality, and material consumption on the actual shop floor.
Data has to flow both directions — orders down from ERP, actual production data up from MES — and most digital transformation projects stall at this integration point rather than at either system individually.
Mapping the actual order-to-cash and plan-to-produce workflows before choosing software tends to produce smoother implementations than selecting a platform first and figuring out the workflow afterward.
