What are Batch Control Systems?
A Batch Control System is software that plans, executes, monitors and records recipe-based batch production, so that every batch is made repeatably and remains fully traceable. Nearly all modern batch systems are built on ISA-88 (S88), the international standard for batch control. The system sits between the PLCs or the DCS that drive valves and pumps and the MES that manages production orders and release.
Batch control is typical of food, pharmaceuticals, fine chemicals, cosmetics, paint and brewing: sectors that repeatedly make a defined quantity of product to a fixed recipe and where quality, hygiene and traceability carry a lot of weight.
🧪 What is a batch process?
A batch process turns a finite quantity of raw materials into a finite quantity of product through a fixed sequence of steps. Between two batches the plant can be cleaned, changed over or used for a different product. That distinguishes batch from continuous processes (such as a refinery) and from discrete manufacturing (individual items). The three types are compared in Discrete, Batch and Continuous Processes.
Each batch gets its own batch number, under which all process data, material consumption and quality results are stored. That link is exactly what makes recalls and quality investigations possible.
🎯 What does a Batch Control System do?
| Function | What the system does |
|---|---|
| Recipe management | Manages recipes with versions, parameters and approvals |
| Batch scheduling | Turns production orders into batches and assigns units |
| Procedural control | Executes recipes step by step and supervises transitions |
| Equipment coordination | Allocates units and prevents two batches from claiming the same tank |
| Operation | Operators start, pause and confirm steps via SCADA or an HMI |
| Batch recording | Records every value, alarm, action and deviation per batch |
| Integration | Exchanges orders and results with MES, ERP and LIMS |
The actual control of temperature, pressure or flow stays in the PLC or DCS. The batch system decides what must happen, when, and with which setpoints; the controller decides how it happens physically.
🧱 How does ISA-88 structure a batch system?
ISA approved ISA-88 in 1995 and revised it in 2010 as ANSI/ISA-88.00.01. The IEC adopted Part 1 in 1997 as IEC 61512-1. The standard describes three related models.
| Model | Levels | Purpose |
|---|---|---|
| Physical model | Enterprise → site → area → process cell → unit → equipment module → control module | Structures the plant |
| Procedural model | Procedure → unit procedure → operation → phase | Structures the process steps |
| Recipe model | General → site → master → control recipe | From product knowledge to an executable batch |
The physical model also appears in ISA-95. For batch control the lower four levels matter most: process cell, unit, equipment module and control module. A unit (for example a reactor or mixing vessel) usually processes one batch at a time and is the level at which recipes are bound to equipment. A phase is the smallest procedural step the batch system calls, such as dose, heat or agitate. Phases are usually programmed in the controller, often in SFC or another IEC 61131 language.
Under ISA-88 a recipe has five parts: header (name, version, status), formula (raw materials, quantities, process parameters), equipment requirements, procedure and other information. A master recipe belongs to a specific process cell; for each batch a control recipe is created from it, carrying the batch number and the actual quantities.
🔄 Which parts make up the ISA-88 standard?
| Part | ANSI/ISA | IEC | Subject |
|---|---|---|---|
| 1 | S88.01-1995, revised as 88.00.01-2010 | IEC 61512-1:1997 | Models and terminology |
| 2 | 88.00.02-2001 | IEC 61512-2:2001 | Data structures and guidelines for languages |
| 3 | 88.00.03-2003 | IEC 61512-3:2008 | General and site recipes |
| 4 | 88.00.04-2006 | IEC 61512-4:2009 | Batch production records |
In 2008 the technical report ISA-TR88.00.02 on machine and unit states followed; it is the basis of PackML. The services in a Module Type Package also follow a state model derived from ISA-88.
ISA-88 further defines a control activity model with six activities: recipe management, production planning and scheduling, production information management, process management, unit supervision and process control. Part 1 also gives an example state model for procedural elements that almost every batch system adopts, including Idle, Running, Holding, Held, Paused, Complete, Stopped and Aborted, driven by commands such as Start, Hold, Restart, Pause, Resume, Stop, Abort and Reset.
🏭 What does a batch look like in practice?
Take a 500-litre batch of shampoo in a mixing vessel (the unit):
- Order and recipe - the MES releases an order; the batch system creates a control recipe with a batch number from the master recipe.
- Unit allocation - the system allocates mixing vessel MV-02 and checks that it is clean and available.
- Phase Dose water - the controller opens the valve and stops at 380 litres, measured by a flow meter.
- Phase Heat - heating to 60 °C; the batch system waits until the controller reports Complete.
- Phase Add ingredient - the operator confirms the lot number of the active ingredient on the HMI, so the material genealogy is correct.
- Phase Mix - 10 minutes of agitation; after a fault the phase goes to Held and the operator can continue once it is cleared.
- Sample and release - the LIMS records the analysis; the batch report goes to QA.
- Cleaning - a CIP procedure prepares the vessel for the next product.
The result is a batch report in which every step, value and operator action carries a timestamp.
🔗 How does batch control work with other systems?
| System | Role around batch control |
|---|---|
| PLC / DCS | Executes phases, equipment modules and control modules |
| SCADA / HMI | Operation, alarms and process graphics |
| Historian | Stores time-series data per batch |
| MES | Orders, electronic batch record (EBR), release and KPIs |
| LIMS | Samples, analyses and specifications |
| ERP | Production planning, inventory and costing |
Well-known batch systems include SIMATIC BATCH for Siemens PCS 7, FactoryTalk Batch from Rockwell Automation, Emerson DeltaV Batch, ABB 800xA Batch Management and AVEVA Batch Management (formerly Wonderware InBatch).
🔐 What should you watch for in compliance and security?
In pharmaceuticals, batch records must meet GMP. Electronic records fall under 21 CFR Part 11 of the US FDA (since 1997) and EU GMP Annex 11 from 2011; an extensive revision of Annex 11 was open for consultation until October 2025. Validation usually follows GAMP 5, whose second edition appeared in 2022. In the Netherlands, the Health and Youth Care Inspectorate (IGJ) supervises GMP. The key points are audit trails, electronic signatures and data integrity according to ALCOA+. Outside pharma, a batch system supports ISO 9001, HACCP and compliance in general.
A batch server is also an attractive target: anyone who can change recipes affects product quality without a single alarm going off. Place batch and recipe servers in a dedicated zone according to IEC 62443, handle recipe changes through change management and version control, and keep a tested backup of the recipe database and configuration.
✅ What does batch control deliver?
- Consistency - every batch follows the same approved recipe, regardless of shift or operator
- Traceability - from raw material lot to finished product, the basis for tracking and tracing
- Flexibility - a new product needs a new recipe, not new PLC code
- Reuse - the same phases serve dozens of recipes
- Fewer errors - manual steps are enforced and confirmed
❓ Frequently asked questions
What is the difference between a Batch Control System and a PLC?
A PLC executes the control and the individual process steps (phases), such as opening a valve until a quantity is reached. A Batch Control System decides which phases run in which order with which parameters and records everything per batch. The two work together: the batch system directs, the PLC executes.
Is ISA-88 mandatory for batch control?
ISA-88 is not a legal requirement but a voluntary standard. In practice almost all commercial batch systems follow the ISA-88 models and terminology. That makes recipes, phases and batch records portable and understandable for vendors, integrators and auditors.
What is the difference between a master recipe and a control recipe?
A master recipe is the approved recipe for a specific process cell, with the standard quantities and the procedure. A control recipe is a copy of it for a single batch, extended with the batch number, the allocated units and the actual values. The control recipe is executed during the batch and forms the basis of the batch record.
What is an electronic batch record (EBR)?
An electronic batch record is the digital record of everything that happened while a batch was produced: materials, process data, actions, deviations and approvals. The Batch Control System supplies the process data, while the MES often assembles the complete record. In pharmaceuticals an EBR must comply with EU GMP Annex 11 and, when supplying the US market, with 21 CFR Part 11.
Can batch control be used in the food industry?
Yes, batch control is widespread in dairy, breweries, sauces and confectionery. There the focus is on allergen traceability, HACCP checks and efficient product changeovers; EU food law (Regulation 178/2002) also requires you to trace every ingredient one step back and every product one step forward. The same ISA-88 principles apply as in pharmaceuticals, although the validation requirements are usually lighter.
How do you secure a Batch Control System?
Place the batch server in a protected network zone and restrict recipe changes to a small group with individual accounts. Make every recipe change pass through an audit trail and an approval, and monitor the integrity of the recipe database. Patch and back up the system on a fixed schedule that respects production windows.
📌 In summary
A Batch Control System executes ISA-88 recipes in a structured way and records every batch completely, so that production is repeatable, flexible and demonstrably under control.
The system separates product knowledge (the recipe) from equipment (the phases in the PLC or DCS), works alongside MES, LIMS and the historian, and in regulated sectors forms the basis for GMP-compliant batch records. Treat recipes as critical data, with strict access control and change management.