IoT vs SCADA: Which is Right for You?
Both IoT and SCADA monitor industrial processes — but they differ in architecture, cost, scalability, and capability. Understand when to use each, or combine them for maximum value.
Industrial IoT (IIoT)
The Industrial Internet of Things connects sensors, devices, and machines to cloud or edge platforms via IP-based networks. IoT emphasizes scalability, data analytics, and remote access.
- Cloud-native architecture
- IP-based communication (MQTT, HTTP, WebSocket)
- Scalable to thousands of devices
- Advanced analytics & machine learning
- Low per-device cost
- Remote access from anywhere
SCADA Systems
Supervisory Control and Data Acquisition systems have been the backbone of industrial automation for decades. SCADA excels at real-time process control and reliable, deterministic communication.
- Proven 30+ years in industry
- Deterministic real-time control
- Proprietary protocols (Modbus, DNP3)
- High reliability & uptime
- Operator HMI interfaces
- Air-gapped security model
Detailed Comparison
| Feature | IoT | SCADA |
|---|---|---|
| Architecture | Cloud/Edge, distributed | Centralized, on-premise |
| Scalability | Highly scalable (1000s of devices) | Limited by infrastructure |
| Communication | MQTT, HTTP, WebSocket | Modbus, DNP3, OPC-DA |
| Latency | Variable (50ms–2s) | Deterministic (<10ms) |
| Cost per Point | Low ($5–50/sensor) | High ($200–2000/point) |
| Data Analytics | Advanced ML/AI built-in | Basic trending & alarming |
| Remote Access | Native cloud access | Requires VPN/special setup |
| Security Model | Zero-trust, TLS, OAuth | Air-gap, proprietary |
| Deployment Time | Days to weeks | Weeks to months |
| Real-time Control | Soft real-time | Hard real-time |
When to Use Each
Choose IoT When...
- You need to monitor hundreds or thousands of data points
- Remote access and cloud analytics are important
- You want to leverage AI/ML for predictive insights
- Budget per data point is a concern
- You're starting a greenfield monitoring project
- Multi-site visibility from a single platform is needed
Choose SCADA When...
- Hard real-time control (<10ms) is mandatory
- You operate safety-critical processes (SIL-rated)
- Air-gapped security is required by regulation
- You have existing SCADA infrastructure to leverage
- Operator HMI screens are mission-critical
- Deterministic communication is non-negotiable
The Hybrid Approach
Many modern plants are adopting a hybrid IoT + SCADA architecture — keeping SCADA for mission-critical control while layering IoT for monitoring, analytics, and AI-powered insights.
Keep Existing SCADA Investment
Don't rip and replace — extend SCADA with IoT data collectors and cloud analytics.
Add AI on Top
Use IoT to feed AI models while SCADA handles the real-time control loop.
Gradual Migration Path
Move to IoT incrementally — start with monitoring, then add control as trust builds.
Unified Dashboards
Combine SCADA and IoT data in a single view for operators and managers.