What is the difference between Discrete, Batch and Continuous processes?
Industrial environments distinguish between three main types of production processes:
- Discrete processes
- Batch processes
- Continuous processes
Each process has its own dynamics, control strategy and automation approach.
This classification is essential when designing SCADA, PLC and MES systems, and when choosing Sensors, data storage and control logic.
🔹 Discrete processes
Characteristics:
- Produce separate units or objects
- Every step is usually clearly distinguishable
- Stop-start character
- Often use assembly lines or robotics
Examples:
- Assembly of cars, appliances or furniture
- Packaging of boxes or bottles
- Printing and labelling of products
Automation:
- Often based on PLC control and logic sequences
- Many IO signals (sensors, actuators)
- HMI for operator control per line or station
🔸 Batch processes
Characteristics:
- Produce in defined quantities (“batches”)
- Each batch follows a recipe
- Processes can be changed between batches
- Highly traceable and controllable
Examples:
- Food preparation (e.g. sauces, chocolate, yoghurt)
- Pharmaceutical production (e.g. tablets or serums)
- Mixing of chemicals or paint
Automation:
- Often S88-based Batch Control Systems
- Recipe management and sequential control
- Strict traceability via MES or Historian
- CIP procedures between batches
🔻 Continuous processes
Characteristics:
- Production runs 24/7 without interruption
- Raw materials are continuously fed in, finished product flows out
- Difficult or expensive to shut down
- High degree of process integration and stability required
Examples:
- Oil and gas refining
- Water treatment
- Steel or paper production
- Chemical reaction processes
Automation:
- Continuous control loops via PID controllers
- DCS systems (Distributed Control Systems) widely used
- Critical parameters such as temperature, pressure and flow monitored in real time
- Typically integrated with Historian and Alarm Management
🧯 Summary
| Process type | Description | Examples |
|---|---|---|
| Discrete | Discrete, countable products or actions | Cars, assembly, packaging |
| Batch | Series production with recipe-driven processes | Food, pharma, paint, chemicals |
| Continuous | 24/7 uninterrupted process without clear end points | Refining, paper, water treatment |
📌 In summary
Discrete processes are step-by-step, batch processes are recipe-driven per series, and continuous processes run uninterrupted. Each type requires its own approach to automation, monitoring, safety and data processing.