The ISA-95 Model Explained
From the Sensor to the C-Suite:
Every Layer. Every Connection. In Sync.
What is ISA-95 and Why Does it Matter?
Utilizing the ISA-95 model allows us to build systems that actually work together, not just on paper.
ISA-95 is an international standard for integrating enterprise systems with industrial control systems. It establishes a common architecture that enterprises can apply to their systems so that real-time decisions are based on real-time data.
Why Does it Matter?
Scalable, Future-Ready Architectures
Break down data silos with a structured approach that scales with your operations.
Data to Decisions
Create a secure data path from the sensor to the C-Suite, turning real-time data into actionable insights.
Seamless Integration
Help all plant systems communicate at the right level without manual data entry and one-off interfaces.
Cybersecurity Zones
Ensure the control environment is secure from risks on the business network with proper segmentation.
The ISA-95 Levels
Understanding each layer of the industrial automation stack
Enterprise & Cloud
Level 5 is the enterprise and cloud layer that takes information from the business network and utilizes Industry 4.0 tools such as Digital Twins, AI Analytics, and Cloud Computing to do more with data and aggregate information from multiple sites for wider enterprise use.
Key Components:
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Business Network
Level 4 is the business network. This is what process engineers use and has connectivity to the internet. There is typically a data historian database on this side of the DMZ that mirrors L3, where Historian clients reside. This is also where supply chain management and ERP systems live.
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DMZ
The DMZ (Level 3.5) is the cybersecurity layer that separates OT from IT. It contains Anti-Virus/Patch/WSUS servers for keeping the OT side up to date with the latest cyber revisions, remote access servers, and is often separated from OT and IT with firewalls or unidirectional gateways that physically prevent data from flowing from IT to OT.
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Manufacturing Operations Management
Level 3 bridges business decisions and automation. It includes MES (production orders, recipe management, downtime tracking, quality), asset management, an OT-side Historian, and OPC servers. This layer also has the OT-side Domain Controller for user management separate from IT.
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Monitoring & Control
Level 2 is the monitoring and control layer where industrial control systems (DCS and PLC) reside and control the process. The Operator Workstations, where the plant is operated from, also reside here.
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Sensing & Manipulation
Level 1 consists of all the instrumentation, valves, and VFDs that measure and control the process. This is the sensing and manipulation layer that interfaces directly with the physical equipment.
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Physical Process
Level 0 is the physical process itself. These are the turbines that generate power, pumps and motors that move fluid, reactors and distillation columns that make final products, cooling towers, boilers, compressors that provide utilities, and any other physical equipment in the field.
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Breaking Down Data Silos
Data tends to get siloed at the Level 2 layer, making it significantly harder to use. Not all information is available in the right format for making the best business decisions.
Having the right components to normalize and contextualize data at Level 3 is key to ensuring true higher-level integration of OT data—enabling the insights that drive operational excellence.
Ready to align your systems with ISA-95?
We help industrial facilities implement ISA-95 compliant architectures that break down silos and turn data into decisions.