Batch Control in Manufacturing

What is Batch Control?

Batch Control refers to the automated execution of batch-oriented processes: raw materials are processed according to recipes in defined steps until a batch is complete.

Typical application fields:

• Pharma, chemicals, food & beverage
• Paints, coatings, adhesives
• Mixing, reaction, and fermentation processes

Batch Control fundamentally answers three questions:

• What is being produced? (Recipe)
• How does the process run? (Procedure)
• What equipment is used? (Equipment)

Relationship to ISA-88

The international standard ISA-88 (IEC 61512) provides the reference model for batch control:

• Process Model: Process, stages, operations, actions
• Physical Model: Enterprise, site, area, process cell, unit, equipment module, control module
• Procedural Model: Recipe procedure, unit procedures, operations, phases
• Recipe Model: General, site, master, control recipe

Essential principles:

• Separation of procedure (recipe) and equipment (plant)
• Modularization into reusable building blocks (phases, modules)
• Uniform terminology for process engineering, automation, MES, and IT

Practically, this means: The same master recipe can run on multiple plants with slightly different configurations without reprogramming the complete logic every time.

Building Blocks of Batch Control

1. Recipes

A batch recipe defines:

• Target product and batch size
• Materials, quantities, setpoints (temperatures, times, agitator speeds, etc.)
• Process sequence (unit procedures, operations, phases)
• Equipment requirements and parameter windows

Typically distinguished between:

• Master Recipe: Approved standard definition
• Control Recipe: Instantiated recipe copy for a specific batch

2. Procedural Control

The procedural model controls execution:

• Starting, pausing, resuming, aborting a batch
• Step-by-step execution of phases (e.g., "heat," "dose," "mix," "cool")
• Transition conditions and interlocks (e.g., temperature reached, valve closed, tank available)

This determines when which actions occur in which sequence—independent of which specific unit ultimately executes them.

3. Equipment & Module Structure

The physical model ensures recipes aren't "welded" to a single plant:

• Unit: e.g., reactor, mixer, fermenter
• Equipment Modules: e.g., dosing station, heating/cooling circuit, CIP unit
• Control Modules: Valves, motors, controllers, scales

Batch Control uses this structure to map phases to equipment and control modules. This makes processes change-friendly and scalable.

Typical Functions of a Batch Control System

A batch control system (often part of a process control system or MES) handles:

Recipe Management: Versioning, approval workflows, audit trail, change management

Batch Scheduling & Dispatching: Planning and starting batches on available units, considering cleaning/CIP/SIP

Online Control & Monitoring: Visualization of running batches (step, status, setpoint/actual values, alarms)

Batch Record & Historization: Complete capture of parameters, operator interventions, deviations—foundation for QA, QP review, audits

Reporting & Analysis: Batch comparison, root cause analysis, OEE and throughput analysis at batch level

Benefits of Batch Control

Professionally implemented batch control delivers:

Quality & Compliance: Reproducible sequences, documented parameter histories, traceability—essential for regulated industries

Flexibility: Adjustment of batch sizes, variants, recipe versions without re-engineering the entire control system

Efficiency: Better plant throughput, fewer operator errors, optimized cleaning and changeover strategies

Standardization: Same recipes and processes across multiple sites, comparable KPIs across plants

Batch Control and MES

Batch Control is classically anchored in the process control system (DCS), but the connection to MES is becoming increasingly important:

• MES manages orders, materials, campaigns and forwards batches to the batch control system
• Batch Control returns detailed batch and history data (times, parameters, deviations)
• MES uses this data for OEE, traceability, performance analysis, PAT approaches (Process Analytical Technology)

In modern architectures, Cloud MES or MOM solutions increasingly handle functions like:

• Plant-wide recipe and master data governance
• Cross-site evaluation of batches and design spaces
• Integration of batch data into digital factory and analytics platforms

Batch Control vs. Continuous / Discrete

Batch: Clearly defined batches, defined start/end points, strong recipe orientation

Continuous: Continuous material flow, focus on stability and control quality over long periods

Discrete: Piece production (parts/units), often with MES logic like workflows, OEE, sequence planning

Many plants run hybrid scenarios (e.g., batch mixers + discrete filling/packaging lines). A unified model and data approach (ISA-88/ISA-95, MES integration) then becomes a decisive architectural advantage.

Quick FAQ on Batch Control

Is Batch Control only relevant for pharma and chemicals? No. Wherever production occurs in defined batches (food, cosmetics, coatings, specialty chemicals), batch control principles make sense—often even without full regulatory complexity.

Do I absolutely need ISA-88 to use Batch Control? Formally no. In practice, an ISA-88-compliant approach saves massive effort because recipes, equipment models, and control modules become reusable and manufacturer-independent.

How does Batch Control fit into a Digital Factory strategy? Batch Control provides granular process and quality data for PAT, OEE, digital twins, and comprehensive analytics. Through MES and data platforms, this data becomes usable for digital factory use cases—from predictive quality to global batch benchmarking.