Implementing ISA-88 Batch Standards in SIMATIC PCS 7 and SIMATIC BATCH Architecture

In SIMATIC PCS 7, compliance with the international ISA-88 (IEC 61512) batch standard is implemented through the integration of SIMATIC BATCH and Sequential Function Chart (SFC) Types. ISA-88 defines a strict separation between physical equipment models and procedural recipe models. In the automation controller (AS), equipment phases (EPH) and equipment modules (EM) are programmed as standardized, reusable SFC Types in the Master Data Library. At the supervisory level, SIMATIC BATCH acts as the recipe execution engine, dynamically allocating units, binding recipe phases to AS SFC Types, and enforcing electronic batch records (EBR) conforming to FDA 21 CFR Part 11 without requiring hard-coded PLC recipes.

Foundational Principles of the ISA-88 (IEC 61512) Standard

The ISA-88 standard (internationally codified as IEC 61512) revolutionizes batch process manufacturing by decoupling physical equipment capabilities from production recipes. In traditional PLC programming, recipes were hard-coded into fixed controller data blocks, requiring costly software re-engineering and re-validation whenever chemical formulations changed.

ISA-88 introduces two independent, interacting hierarchical models:

Physical Model: Defines the plant equipment hierarchy from enterprise level down to discrete field actuators.
Procedural Model: Defines the operational steps required to produce a product, independently of specific physical tanks.

By matching procedural recipe phases to physical equipment phases at runtime, automated plants achieve maximum manufacturing flexibility and multi-product agility.

Mapping the ISA-88 Hierarchy into SIMATIC PCS 7 Architecture

SIMATIC PCS 7 implements the full ISA-88 standard through native engineering and runtime components:

ISA-88 Standard LevelISA-88 Functional DefinitionImplementation in SIMATIC PCS 7Engineering EnvironmentProcess CellComplete production area capable of making a batchPlant Hierarchy Root Folder / SIMATIC BATCH Process CellSIMATIC Manager Plant ViewUnitMajor equipment performing processing activities (e.g. Reactor)Technological Hierarchy Unit Folder with UNIT_PLC blockPlant Hierarchy / BATCH EditorEquipment Module (EM)Functional group performing minor processing (e.g. Dosing)Reusable SFC Type (Equipment Phase / Module)SFC Editor in Master Data LibraryControl Module (CM)Actuator/sensor combination with state feedbackAPL Control Module Types (CMT) (MotL, VlvL)CFC Editor in Master Data LibraryRecipe ProcedureMaster Recipe defining overall multi-unit manufacturingMaster Recipe / Control RecipeSIMATIC BATCH Brec / BCC

This mapping ensures that physical equipment logic resides strictly in the AS controller, while flexible recipe authoring is conducted by process technologists in SIMATIC BATCH.

Step-by-Step Engineering Workflow for ISA-88 Batch Phases

To engineer an ISA-88 compliant batch process in SIMATIC PCS 7, execute the following technical workflow:

Define Plant Hierarchy: In SIMATIC Manager Plant View, structure folders conforming to ISA-88: Plant -> Process_Cell_01 -> Reactor_Unit_01.
Develop Reusable SFC Types in Master Data Library: Open the Master Data Library. Insert an SFC Type named EPH_Dosing. Define the state machine conforming to the ISA-88 state transition diagram (Idle, Starting, Running, Completing, Completed, Holding, Held, Pausing, Paused, Aborting, Aborted, Stopping, Stopped).
Parameterize Batch Interface: In the SFC Type interface, define:
- Control Strategies: E.g., Coarse Dosing, Fine Dosing.
- Setpoints: Material ID, Target Mass (kg), Dosing Speed (%).
- Process Values: Actual Dosed Mass, Material Flow Rate.
Instantiate SFC in Unit Charts: In the AS project, open the CFC chart under Reactor_Unit_01. Drag an instance of EPH_Dosing into the chart. Interconnect the phase logic to technological valves and pumps (VlvL, MotL).
Generate Batch Types: In SIMATIC Manager, select Options -> SIMATIC BATCH -> Compile / Download. The compilation reads all SFC Types and unit definitions, generating the SIMATIC BATCH engineering dictionary.
Author Master Recipes in SIMATIC BATCH: Open the BATCH Control Center (BCC). In the Recipe Editor, create a Master Recipe. Drag the EPH_Dosing phase into the recipe diagram and parameterize target setpoints.

Verification

Verify ISA-88 batch execution and recipe coordination through these operational steps:

Compile and Download BATCH Types: In SIMATIC Manager, execute SIMATIC BATCH -> Compile. Verify that compilation finishes with 0 Errors and that all Unit and Phase definitions are exported.
Create and Release Control Recipe: In BATCH Control Center (BCC), create a new batch order from the Master Recipe. Release and start the batch.
Online State Machine Execution: Monitor the batch execution in BCC and observe the CFC chart online. Verify that the SFC transitions smoothly from Starting -> Running -> Completing -> Completed, and that recipe setpoints are transferred accurately.

Limitations and Operational Precautions

When implementing ISA-88 batch architectures, observe these regulatory and technical constraints:

FDA 21 CFR Part 11 Compliance: For regulated pharmaceutical and food manufacturing, activate SIMATIC Logon and audit trails in SIMATIC BATCH to enforce electronic signatures, password expiration, and tamper-proof batch archiving.
SFC Type State Transition Rules: Strictly adhere to the standard ISA-88 state logic; bypassing hold or abort states in custom SCL code can cause recipe deadlocks in SIMATIC BATCH.
Commercial Accuracy Notice: SIMATIC BATCH is a separately licensed option package. Licensing is governed by the number of concurrent active BATCH Units (e.g. BATCH Basic, BATCH 10 Units). Always verify license capacity against current Siemens catalogs.

Engineer FAQ

Can I implement ISA-88 in PCS 7 without purchasing SIMATIC BATCH?

Yes. You can program SFC Types and coordinate unit operations using native PCS 7 SFC charts. However, advanced recipe management, flexible formula authoring, and electronic batch reporting (EBR) require SIMATIC BATCH.

What is the difference between an SFC Chart and an SFC Type?

An SFC Chart is a single, hard-coded sequential program placed in a CFC chart. An SFC Type is a reusable class definition stored in the library that can be instantiated across multiple units and dynamically driven by SIMATIC BATCH.