What is ISA-95?
ISA-95 is an international standard for integration between business software (such as ERP) and production systems (such as MES, SCADA, DCS). The standard provides a modelling and terminology framework for structurally linking IT and OT systems.
ISA-95 = the bridge between ERP and the factory floor.
The aim is to prevent confusion, duplicated work and integration issues in automation projects in production environments.
🧠 Why ISA-95?
Without a shared structure, IT and OT often talk past each other:
- ERP wants to “produce quantities”
- OT systems work with “machines, batches and processes”
ISA-95 provides clear data models, a process hierarchy and a common language.
🧱 Core components of ISA-95
| Component | Description |
|---|---|
| Enterprise-Control Model | Hierarchical model of levels within an organisation (see below) |
| Functional Models | Which functions belong at which level (such as planning, scheduling, control) |
| Object Models | Standardised objects such as Material, Product, Equipment, Personnel |
| Activity Models | Which activities are carried out at which level and with what information |
| Data Flow Models | How data flows between ERP ↔ MES ↔ SCADA ↔ Machines |
🧭 The five ISA-95 levels
| Level | Name | Description |
|---|---|---|
| Level 0 | Process | Physical production, machines, sensors, actuators |
| Level 1 | Physical control | PLCs, DCS, direct machine control |
| Level 2 | Monitoring & supervision | SCADA, HMI, alarms, process monitoring |
| Level 3 | Production management | MES: planning, tracking, recipe management, quality, maintenance |
| Level 4 | Business level | ERP: order management, supply chain, finance, HR, business rules |
| This aligns with the Purdue Model |
🔗 ISA-95 in practice
Without ISA-95:
- Every link between ERP and production is custom-made
- Duplicate data models, inconsistent terminology
- High risk of misunderstandings and integration issues
With ISA-95:
- ERP knows when production is finished or has stopped
- MES receives orders as standardised production instructions
- SCADA/PLC provide feedback to ERP via MES
- Data integration becomes reusable, scalable and future-proof
🔁 ISA-95 vs. ISA-88
| ISA-95 | ISA-88 |
|---|---|
| Integration between IT (ERP) and OT | Standard for batch automation in OT |
| Focuses on information and process structure | Focuses on equipment and recipe-based production |
| Key for ERP ↔ MES projects | Key for batch control and SCADA design |
📌 In summary
ISA-95 provides a framework for connecting ERP, MES and production automation. It makes communication between IT and OT systems consistent, scalable and understandable — essential for Smart Industry and IT OT convergence.