Understand
Responsibilities comparison
The table describes common roles, not a rule for every product.
| Concern | ERP | MES | SCADA |
|---|---|---|---|
| Planning horizon | Orders, materials, finance, broad scheduling | Detailed production dispatch and execution | Current process/equipment supervision |
| Typical identity | Customer order, item, supplier, cost | Work order, operation, batch/serial, resource | Tag, device, alarm, process value |
| Transactions | Purchasing, inventory, completion, costing | Issue, start, complete, consume, inspect | Read/set process values where authorized; alarms and trends |
| Users | Planning, finance, procurement, management | Production, quality, supervisors | Operators and control/automation specialists |
| Control boundary | Business system | Operations information | May interact with industrial control; specialist governance applies |
Understand
Illustrative data flow
An ERP releases an approved work order and bill-of-material revision. An MES dispatches operations and records production, consumption, inspection, and genealogy. Approved SCADA or historian data can provide equipment events to the MES or analytics layer. The MES returns validated completion and consumption to ERP. Exceptions are reconciled; no layer silently overwrites another's master data.
Review
Questions to ask vendors
01Which system owns each master and transaction field?
Record the decision, responsible owner, supporting evidence, and follow-up action.
02What interface is supported and how are retries made idempotent?
Record the decision, responsible owner, supporting evidence, and follow-up action.
03How are corrections, revisions, and late records represented?
Record the decision, responsible owner, supporting evidence, and follow-up action.
04What happens during network loss?
Record the decision, responsible owner, supporting evidence, and follow-up action.
05Can data and configuration be exported?
Record the decision, responsible owner, supporting evidence, and follow-up action.
06Which functions require additional modules or licenses?
Record the decision, responsible owner, supporting evidence, and follow-up action.
07How are access, logs, backup, and support divided?
Record the decision, responsible owner, supporting evidence, and follow-up action.