Information model

An information model is a structured representation of information, including the types of data that exist in a domain, the relationships between those data elements, and the rules or constraints that govern them. In industrial and manufacturing environments, information models are used to describe how equipment, processes, materials, batches, quality records, and business objects are represented and exchanged across OT and IT systems.

Key characteristics

In this context, an information model typically:

• Defines entities and attributes, such as assets, tags, lots, recipes, orders, or alarms, and their properties.
• Specifies relationships, for example how a batch relates to raw material lots, equipment units, and test results.
• Provides structure for interoperability, enabling different systems (PLC/SCADA, MES, LIMS, ERP, historians) to interpret exchanged data consistently.
• Includes rules and constraints, such as allowed value ranges, units of measure, or mandatory fields for regulatory records.

An information model can be formalized in many ways, including OPC UA address spaces, ISA-95 object hierarchies, database schemas, XML or JSON schemas, or model-based integration frameworks. The core idea is to create a common, machine-readable understanding of what the data represents, not just how it is formatted.

Role in industrial and regulated environments

In manufacturing systems, information models commonly:

• Bridge OT and IT by mapping control-level tags and signals to higher-level concepts like equipment units, production runs, or KPIs.
• Support compliance and traceability by explicitly modeling genealogy, batch relationships, and links between process data and quality records.
• Enable standardized interfaces for MES/ERP or MES/LIMS integration by sharing a consistent definition of orders, materials, test results, and status codes.
• Improve data governance by clarifying ownership, meaning, and permissible uses of data elements across systems.

Information models and OPC UA

OPC UA uses the concept of an information model to describe data exposed by devices, controllers, gateways, and applications. In OPC UA:

• The information model defines nodes (objects, variables, methods) and references that organize data into a browseable address space.
• Standard companion specifications add domain-specific models, such as models for machine tools, robots, or packaging lines.
• Vendors can extend the base model with custom types, which makes it important to review and validate each implementation when integrating into a plant.

What it is not

An information model is not the same as:

• Physical data storage, such as a specific database implementation or file format, even though it may influence them.
• A communication protocol; it describes what information is represented, not the low-level mechanics of how bytes are transmitted on the network.
• A process model; it focuses on data representation rather than on the sequencing or control logic of operations.

Common confusion

Several related terms are often used alongside or instead of “information model”:

• Data model: Often used interchangeably, especially in IT. Some practitioners use “information model” for a higher-level, conceptual view and “data model” for more concrete implementation details, but the distinction is not universal.
• Ontology: In some contexts, this refers to a more formal, semantically rich information model with explicit meaning and reasoning rules, for example using semantic web technologies.
• Schema: Typically refers to the technical structure of data in a specific system (such as a database or message format) that is derived from or aligned with an information model.

When specifying or reviewing integrations in manufacturing environments, it is useful to clarify whether a document or standard is describing a conceptual information model, a concrete data/schema design, or both.