[Smart Factory Basics #1] ISA-95: An International Framework
Introduction
Advances in information and communications technology (ICT) have made digital transformation an important part of business innovation. In manufacturing, this transformation is often described through the concept of the smart factory.
When learning about smart factories, unfamiliar terms such as PLC and SCADA can be an immediate obstacle. Rather than studying each term in isolation, it is often easier to understand its role within the overall system.
ISA-95 provides an international framework for understanding and integrating enterprise and manufacturing systems. This article introduces the main concepts through that framework.
An Overview of ISA-95
Commercial MES and ERP packages have historically used different data definitions and interfaces, making integration difficult. This created a need for a common standard for enterprise and control system integration. Work on ISA-95 began in 1995 through ISA (the International Society of Automation), involving major system vendors such as SAP and ABB, within the ANSI standards framework.
The standard helps organizations define and integrate production and related activities across systems, supporting better business decisions.
The Five Levels of ISA-95
Level 0: The Physical Production Process
This level represents the physical production environment that generates data for automation. Raw signals originate from factory floors, facilities, vehicles, and other sources involved in production. Individual measurements can be very small, while the total volume is enormous. Measurements may be taken at millisecond or even microsecond intervals.
The physical environment includes sensors, instruments, smart starters, and other devices that provide real-time measurements.
Engineering work in this area covers the installation, electrical connection, configuration, and programming of equipment such as:
Sensors, detectors, analyzers, and intelligent instruments
RFID and barcode readers
Scanners and cameras for machine vision
Power quality monitoring (PQM) systems
Smart starters, overload relays, variable-frequency drives, and motors
Valves and actuators with intelligent positioners
Industrial and collaborative robots
Weighing and dosing systems
Fieldbuses and real-time industrial networks, including EtherNet/IP, PROFINET, Modbus TCP, EtherCAT, HART, DNP3, IEC 61850, and OPC UA
Level 1: Sensing and Manipulation
Level 1 covers sensing and manipulating the manufacturing process. Sensors and other connected devices collect data and transmit it to controllers or subsystems.
Assets may be sensed—for example, by measuring temperature, pressure, or cycle counts—or manipulated, such as by closing a valve or switching equipment on or off.
Engineering, installation, connection, configuration, and programming in this area involve systems such as:
Industrial controllers and programmable logic controllers (PLCs)
Distributed control systems (DCS)
Safety instrumented systems (SIS)
Data aggregation can occur at this level. Technology and automation connected to physical sensors can put readings into context and turn them into meaningful information.
Level 2: Monitoring and Supervisory Control
This level concerns monitoring and controlling the manufacturing environment, working with I/O subsystems, logic solvers, and controllers. For example, an accelerometer can send vibration data to a PLC, which can stop a machine when vibration exceeds its permitted range.
The same principle applies to many sensor-and-control combinations. The sensors need to be connected to the relevant subsystem, logic solver, or controller through the industrial communications infrastructure.
Typical systems include:
Human-machine interfaces (HMI)
Supervisory control and data acquisition (SCADA)
HMI and SCADA systems can display thousands of readings per second as trends and support historical analysis. Technologies such as SQL, REST APIs, XML, OPC UA, and MQTT enable bidirectional data exchange with higher-level systems in the automation hierarchy.
Level 3: Manufacturing Operations Management
Level 3 includes workflows that help achieve production goals, such as scheduling, balancing workloads, and optimizing production through manufacturing execution systems (MES).
Software such as computerized maintenance management systems (CMMS), SCADA, and advanced process control (APC) supports plant activities including quality, production, information integrity, emissions, and maintenance.
These workflows extend beyond equipment control. They also guide people in coordinating automated and manual activities across the plant.
Systems and applications at this level include:
Databases such as Microsoft SQL Server and Oracle
Production, environmental, and event reports
Dashboards with key performance indicators, such as Excelpro’s MIA application
Recipe and batch management
Manufacturing execution systems (MES)
Material handling and storage management
Quality management
Level 3 brings industrial IT activities together: data collection, production scheduling, workforce and resource management, product and batch tracking, genealogy, quality and process management, performance analysis, documentation, and maintenance. Its purpose is to integrate these activities vertically with the other levels.
Level 4: Business Planning and Logistics
Level 4 aligns business goals with manufacturing operations through enterprise systems such as ERP, supply chain management (SCM), and maintenance planning systems.
Decisions at this level concern business and logistics matters such as production quantities and raw materials. Information from Level 3 is essential to making those decisions well.
Vertically integrating ERP with plant operations gives the business a clearer, timely view of operating conditions and supports effective decisions.
What ISA-95 Means for Smart Factories
A smart factory applies ICT to production, collects process data through connected equipment, and uses analysis and control to improve manufacturing efficiency. ISA-95 provides a framework and common reference for integrating the systems involved.
The framework establishes consistent terminology across manufacturing operations. It also helps visualize the relationship between the physical and digital worlds.
The levels are often shown as a pyramid. This is more than an organizational hierarchy: it represents how large volumes of data collected at the bottom are filtered, combined, processed, and analyzed, becoming information that can be used at successive levels.
This article has outlined where the main smart factory components fit and what they do. A future article will examine individual components, including PLCs and SCADA, in greater detail.
